Communication and Network

Communication & Network

Twisted-Pair

Twisted pair is the ordinary copper wire that connects home and many business computers to the telephone company. To reduce crosstalk or electromagnetic induction between pairs of wires, two insulated copper wires are twisted around each other. Each connection on twisted pair requires both wires. Since some telephone sets or desktop locations require multiple connections, twisted pair is sometimes installed in two or more pairs, all within a single cable. For some business locations, twisted pair is enclosed in a shield that functions as a ground.

Coaxial Cable

Coaxial cable is the kind of copper cable used by cable TV companies between the community antenna and user homes and businesses. Coaxial cable is called "coaxial" because it includes one physical channel that carries the signal surrounded (after a layer of insulation) by another concentric physical channel, both running along the same axis. The outer channel serves as a ground. Many of these cables or pairs of coaxial tubes can be placed in a single outer sheathing and, with repeaters, can carry information for a great distance.

Fiber-optic cable

The Communications Services department has installed fiber optic cable between many buildings on the UCSB main campus. New buildings are added to the ring as they are built. The Office of Information Technology also adds fiber segments as part of its Next Generation Backbone development. This cable plant is used to support high speed data communications and parts of the campus CATV network, but may eventually also support voice communications.

Secondary Storage

Secondary storage

Disk Caching

It is a mechanism for improving the time it takes to read from or write to a hard disk. Usually it is included as part of the hard disk. It can also be a specified portion of random access memory (RAM). The disk caching holds data that has recently been read and in some cases adjacent data areas that are likely to be accessed next.

Redundand arrays of inexpensive disk (RAID)

RAID can be implemented as Hardware or Software. A hardware RAID system requires a dedicated RAID Controller, on the other hand a software RAID doesn't require any additional hardware and is bundled as a feature in the operating system. Since hardware RAID employs dedicated controller setup for its implementation, it has performance benefits over the software RAID.

File compression and decompression

Image compression is minimizing the size in bytes of a graphics file without degrading the quality of the image to an unaccceptable level. The reduction infile size allows more images to be stored in a given amount of disk or memoryspace. It also reduces the time required for images to be sent over the Internet or downloaded from Web pages.

Input & Output

Magnatic Ink Character Recognition (MICR)

It is a technique that enables special characters printed in magnetic ink to be read and input rapidly to a computer. MICR is beneficial and it works efficiently in banking because magnetic-ink characters can be machine-read as it more accurate compare to human reading or other optical character recognition (OCR) systems, and are therefore it is ideal for marking and identifying the account and sort code numbers on cheques.

Optical Character Recognition (OCR)

It is also known as OCR. It is the mechanical or electronic translation of images of handwritten, typewritten or printed text (usually captured by a scanner) into machine-editable text.
OCR is a field of research in pattern recognition, artificial intelligence and computer vision. Though academic research in the field continues, the focus on OCR has shifted to implementation of proven techniques.

Optical Mark Recognition (OMR)

Optical Mark Recognition (OMR) is the technology of electronically extracting intended data from marked fields, such as checkboxes and fill-in fields, on printed forms. It is different from OCR by the fact that a recognition engine is not required. The image is required to have high contrast and an easily-recognizable or irrelevant shape.

Dot Matrix Printer

A type of printer that produces characters and illustrations by striking pins against an ink ribbon to print closely spaced dots in the appropriate shape. Dot-matrix printers are relatively expensive and do not produce high-quality output. However, they can print to multi-page forms (that is, carbon copies), something laser and ink-jet printers cannot do.

Plotter

A device that draws pictures on paper based on commands from a computer. Plotters differ from printers in that they draw lines using a pen. As a result, they can produce continuous lines, whereas printers can only stimulate lines by printing a closely spaced series of dots. Multicolor plotters use different-colored pens to draw different colors. In general, plotters are considerably more expensive than printers. They are used in engineering applications where precision is mandatory.

Photo Printer

A printer specialized for smaller prints. When first introduced in the mid-1990s, photo printers used dye sublimation for high quality printing because inkjet printing was not quite up to par. Since then, inkjet technology has greatly improved, and most photo printers are inkjets. Epson, Canon and HP are major players in this market. See digital camera, phot scanner, inkjet printer and dye sublimation printer.

Portable Printer

A portable computer is a personal computer that is designed to be easily transported and relocated, but is larger and less convenient to transport than a notebook computer. The earliest PCs designed for easy transport were called portables. As the size and weight of most portables decreased, they became known as laptop computer and later as notebook computer. Today, larger transportable computers continue to be called portable computers. Most of these are special-purpose computers - for example, those for use in industrial environments where they need to be moved about frequently.

Fax Machine

It is using affordable devices operating over the telephone network. Senders are able to send document to large distances receiver instantly. Yet it has disadvantages, in quality have relegated it to a position beneath email as the prevailing form of electronic document transfer except where the legal status of a sent fax and its accompanying sending report are desired.

Multifunctional Device

Multifunction Device (MFD), is an office machine which incorporates the functionality of multiple devices in one, so as to have a smaller footprint in a home or small business setting, or to provide centralized document management/distribution/production in a large-office setting.

Internet telephones

Internet telephone is the use of the Internet rather than the traditional telephone company and rate structure to exchange spoken or other telephone information. Since access to the Internet is available at local phone connection rates, an international or other long-distance call will be much less expensive than through the traditional call arrangement.

System Unit

Expansion Card

Expansion card is known as an electronic card with the ability to connect to the other computer. that can be installed in computer to add functionality to it such as PCI slots. Expansion cards are installed into the expansion slot of a computer motherboard. They enhance the computer’s ability to perform additional functions not offered by the motherboard. Video cards and sound cards are common examples of PC expansion cards.

Network Interface Card


A network interface card is used to connect a computer to an Ethernet network. It provides an interface to the media. The card usually also contains the protocol control firmware and Ethernet Controller needed to support the Medium Access Control (MAC) data link protocol used by Ethernet. A unique 48-bit serial number is being contained by the Ethernet which is known as MAC address, it is stored in ROM carried on the card. It iscompulsory for every computer on an Ethernet network must have a card with a unique MAC address.

Cache Memory
A memory cache, sometimes called a cache store or RAM cache, is a portion of memory made of high-speed static RAM (SRAM) instead of the slower and cheaper dynamic RAM (DRAM) used for main memory. Memory caching is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in SRAM, the computer avoids accessing the slower DRAM.

Plug and play

Plug and Play, sometimes, abbreviated PnP, is a catchy phrase used to describe devices that work with a computer system as soon as they are connected. The user does not have to manually install drivers for the device or even tell the computer that a new device has been added. Instead the computer automatically recognizes the device, loads new drivers for the hardware if needed, and begins to work with the newly connected device.

Socket





A computer program needs to connect to a local or wide area network such as the Internet, it uses a software component called a socket. It opens the network connection for the program, allowing data to be read and written over the network. It is important to note that these sockets are software, not hardware, like a wall socket. Sockets are a key part of Unix and Windows-based operating systems. They make it easy for software developers to create network-enabled programs.


Chips

A small piece of semiconducting material (usually silicon) on which an integrated circuit is embedded. A typical chip is less than ¼-square inches and can contain millions of electronic components (transistors). Computers consist of many chips placed on electronic boards called printed circuit boards.
There are different types of chips. For example, CPU chips (also called microprocessors) contain an entire processing unit, whereas memory chips contain blank memory.

Slots



An opening in a computer where you can insert a printed circuit board. Slots are often called expansion slots because they allow you to expand the capabilities of a computer. The boards you insert in expansion slots are called expansion boards or add-on boards. Slots are different from BaysBays are sites within the computer where you can install disk drives. Typically, slots are in the back of the computer and bays are in the front.


Bus lines


The bus lines are the communicating electronic lines that connect different parts of the CPU to various other parts. In addition, the bus lines also link the CPU to different parts on the system board of your computer. The data flows in the form of bits along the bus lines. The bus lines are like multilane pathway which means that the more bus lines are on the system the greater is the rate of transfer of data along the bus, which means that the computer can run efficiently and will perform the operations at a faster rate.



Serial port



An Asynchronous port on the computer used to connect a serial device to the computer and capable of transmitting one bit at a time. Serial ports are typically identified on IBM compatible computers as COM (communications) ports. For example, a mouse might be connected to COM1 and a modem to COM2. With the introduction of USB, FireWire, and other faster solutions serial ports are rarely used when compared to how often they've been used in the past. To the right is a close up of a DB9 serial port on the back of a computer.

Parallel Port







A parallel interface for connecting an external device such as a printer. Most personal computers have both a parallel port and at least one serial port. A newer type of parallel port, which supports the same connectors as the Centronics interface, is the EPP (Enhanced Parallel Port) or ECP (Extended Capabilities Port). Both of these parallel ports support bi-directional communication and transfer rates ten times as fast as the Centronics port.
Macintoshes have a SCSI port, which is parallel, but more flexible.


Universal Serial Bus


Universal Serial Bus (USB) is a set of connectivity specifications developed by Intel in collaboration with industry leaders. USB allows high-speed, easy connection of peripherals to a PC. When plugged in, everything configures automatically. USB is the most successful interconnect in the history of personal computing and has migrated into consumer electronics (CE) and mobile products.

Firewire Port




A high-speed serial bus that was developed by Apple, Texas Instruments and others via the IEEE. Standardized as the IEEE 1394 High Performance Serial Bus (HPSB), FireWire supports 63 devices, real-time data transfer, hot swapping and simultaneous multiple speeds. It is widely used to download video from digital camcorders to the computer and is also used in other A/V applications.

The Internet, The Web and Electronic Commerce

HTML








HTML is the abbrevation of Hypertext Markup Language. It ables to load script in the form of Java Script. It is always intended for display on a World Wide Web browser page. It provides some additional non-standard codes. The current version of HTML is HTML 4.0. The more advanced features of HTML 4 had been used by the web developers to design pages for both browsers and send out the appropriate version to a user. It also used to structure text and multimedia documents to set up hypertext links between documents.

Java Script

Java Script is a user interface scripting language developed by Netscape. Java Script source code is embedded in HTML documents, and is interpreted by a World-Wide Web browser. Java source code is compiled into a bytecode, stored in a separate file, which the World-Wide Web browser downloads and executes separately from an HTML page. It is highly evolved and help users to focus on their applications. For example users can do things without the page having to be send back to the server, such as validate form input.







APPLETS

The applet is used to embed Java applets. It has been deprecated in HTML in favor of the more generalized object element. However, since the few browsers that support object do so with significant bugs, applet is currently a more reliable method of embedding Java applets. applets loaded over the net are prevented from starting other programs on the client. Applets loaded over the net are also not allowed to load libraries, or to define native method calls. If an applet could define native method calls that would give the applet direct access to the underlying computer.

Business to Consumer E-commerce

Business to consumer e-commerce is the relationship between businesses and individual consumers through online transaction. It is also known as B2C model or transaction. It helps business to sell products and services through online retail sales. Manufacturer will be able to sell it to the consumers easily. Consumer will find it cheaper in price and the delivery is quick. Design of the product tat being sell in the market must be eye-catching in order to catch the consumer's attention.

Consumer to Consumer E-commerce

Consumer to consumer e-commerce is also known as C2C. It is a transaction between or among consumers. Consumers will sell goods and services to other consumers. It will be cheaper and smaller but profitable. The owner of the business does not have to rent a place to sell their products. The transaction will continue to grow and it will prevent it from being diminished.

File Transfer Protocol

File transfer protocol is used to transfer program or other information from one computer to another. It is usually used to transfer web pages file from their creator to the computer. It offers a graphical user interface with a commercial program. Furthermore, programs can be downloaded from the choosen web page. It is usually provided as part of a suite of programs that come with TCP/IP.

Filters

Filters is a pattern that allow the mathces data to pass through. It only accept certain types of data as input. Unwanted frequencies from an input signal will be eliminated. A wide range of types of filters will present an overview.

Career in IT

Webmaster

Webmaster is mainly know as a person who is responsible for maintaining a website. It generalists by HTML expertise. The expertise are required to know how to configure web servers and server administrator. Webmaster helps businessperson to sell products and services. Main responsibilities of the webmaster are the regulation and the management of access right. It is not merely cover the technical aspect of overseeing website construction and maintenance.

Computer support specialist

People who are working as computer support specialist had provided a lot of help for the computer users. Usually, they make the computer software for place such as a school. Sometimes the software marker would like to ask their opinions and ideas for the new product. More of these workers will be needed because the number of computers and their level of complexity are rising. The occupation is divided into two categories: technical support specialists and help-desk technicians. Technical support specialists answer telephone calls from users of their company's computers. Help-desk technicians help computer users with some of the questions not answered in instruction manuals.

Technical writer

Technical writer are professional writer who able to specialize in intellectual property rights registrations such as filing of patent, trade mark and industrial design. The origins of technical writing have been variously attributed to Ancient Greece, the Renaissance, and the mid-19th century.Technical writers consistently get paid well to use their writing talent. They used information Development, User Assistance, Technical Documentation, or Technical Publications as their references. Perhaps it is usually become the subject of the parody due to the poor quality technical documents. But, it is difficult writing issues as they have to consider the audience and the sources that been used.

Software engineer

Computer software engineers apply the principles of computer science and mathematical analysis to the design, development, testing, and evaluation of the software and systems that make computers work. They have to analyze users’ needs and design, construct, and maintain general computer applications software or specialized utility programs. Their performances evolve quickly due to new areas of specialization or changes in technology. Computer software engineers begin to analyze users’ needs, and then design, test, and develop software to meet those needs. They are creating the detailed sets of instructions, known as algorithms.It tells the computer to convert these instructions into a computer language. It is presented in pseudocode.

Network administrator

Network administrator is an advance profession for the maintenance of computer hardware and software. It comprises a computer network that include maintenance and monitoring of active network equipment. A network administrator will be dealing with patching systems and locking down systems. It is a rather highly technical role as only authorized personal can access and use them. It is essential for them to know about the network operating systems, network equipment and networking protocols. These basic abilities to program scripts and batch files are crucial for network administrator.

Database administrator

Database administrator had been creating varities of helpful and usefull programmes such as the Internet and electronic commerce (e-commerce) which generate lots of data. Data must be stored, organized, and managed. They must ensure that the systems work and perform like what they expect to identify user needs, set up computer databases, and test systems. Data integrity, backup, and security have to be downloaded into the programme which are critically parts of the job. Data will remain consistent across the database and clearly defined.

System analyst

System analyst have the responsibility to identifying and describing problems about implementing a new automated or manual system or changing an existing application system. A new or changed systems can be used by appropriate technology, tools, and methods. Users must be assited to prepare for the installation and start-up of any new system. System analyst should also have the following knowledge such as business knowledge, interpersonal skills and problem solving skills.

Programmer

A programmer main job is programming. The computer will follow the programmer's instructions. Such as converting a design into a logical series of instruction. Programmers will follow the specifications given by computer software engineers and systems analysts. On the other hand, programmer will update, repair, modify as well as expanding existing programmes. Their abilities knowing more than one language make them to learn languages easily.Computer programmers often are grouped into two broad types: applications programmers who write programs to handle a specific job and systems programmers who write programs to maintain and control computer systems software for operating systems, networked systems, and database systems.