Lesson1 ADET-intro to hardwarre & basic IT

Computer Hardware

set of physical parts or can be seen from the naked eye

Central Processing Unit (CPU)

The part of the computer that consists of three associated elements: the arithmetic/logic unit, the control unit, and the register areas.

Arithmetic/Logic Unit (ALU)

The part of the CPU that performs mathematical calculations and makes logical comparisons.

Control Unit

The part of the CPU that sequentially accesses program instructions, decodes them, and coordinates the flow of data in and out of the ALU, registers, primary storage, and even secondary storage and various output devices.

Register

A high-speed storage area in the CPU used to temporarily hold small units of computer-generated instructions and data immediately before, during, and after execution by the CPU.

Primary Storage

(main memory; memory)The part of the computer that process program instructions and data.

Instruction time (I-time)

The time it takes to perform the fetch-instruction and decode instruction steps of the instruction phase.

Execution time (E-time)

The time it takes to execute an instruction and store the results.

Machine Cycle

The instruction phase followed by the execution phase.

Pipelining

A form of CPU operation in which multiple execution phases are performed in a single machine cycle.

Application

A computer program that does specific tasks such as word processing or spreadsheets.

Bit

Represents a binary digit which is the amount of information obtained by asking a ‘yes’ or ‘no’ question. This is also the smallest unit of information stored on a computer as a 0 or 1.

Blinking Cursor

This is a vertical blinking bar that locates the position on the screen where text can be inserted or deleted. This appears most frequently in text or dialog boxes.

Byte

Data is stored on a computer in Bytes. A byte is one character, which may be a number or letter. A byte is composed of 8 consecutive bits. 1,000 bytes = 1 kilobyte (K or KB) 1,000 KB = 1 megabyte (MB) 1,000 MB = 1 gigabyte (GB) 1,000 GB = 1 Terabyte (TB)

Cache

This is a type of memory and is similar to RAM. Cache is used by the computer to move data between the RAM and CPU.

CD-ROM

A removable disk that stores data. A CD-ROM can only be read. You cannot record (save) data onto one. You may however record (save) onto a

CD-Rewritable

disk. This is most often called a CD. A CD looks like a music CD, but contains data instead of music .

CPU

The CPU (central processing unit), is the brain of the computer. New Windows-based programs use a Pentium processor primarily.

DVD (Digital Versatile Disc)

Technology that store more information than a CD-ROM and can be written.

File

A collection of data with a name.

Flash Drive

This is a small portable hard drive that plugs into a USB port and allows you to transport files between different computers. Also called a thumb drive.

Graphical User Interface (GUI)

A program that helps you more easily work with you operating system and application programs by providing pictures and visual clues to help you work. Windows is the GUI on PCs.

Hard Drive

The place where programs and files are stored in a computer.

Random Access Memory (RAM)

The amount of temporary storage that you can use at one time. Memory stores ends when the computer is shut down.

Modem

This is a way to transfer data through a telephone or cable line generally by the Internet. It may be internal or external. Some modems are used to fax or act as answering machines.

Monitor

Similar to a television screen, the monitor allows you to see the data on your computer.

Motherboard

The circuit board that functioning parts of the computer connect to the motherboard. The CPU, RAM and cache all plug into the motherboard.

Mesh Topology

Each device is connected to every other device on the network through a dedicated point-to-point link

Star Topology

Each device in the network is connected to a central device called hub. Unlike Mesh topology, star topology doesn’t allow direct communication between devices, a device must have to communicate through hub

Bus Topology

The main cable and all the devices are connected to this main cable through drop lines. There is a device called tap that connects the drop line to the main cable.

Ring Topology

Each device is connected with the two devices on either side of it. There are two dedicated point to point links a device has with the devices on the either side of it. This structure forms a ring thus it is known as ring topology.

Hybrid Topology

Combination of two or more topology is known as hybrid topology. For example, a combination of star and mesh topology is known as hybrid topology.