Appendix A: Hardware and Software Basics

Hardware

Consists of the physical devices associated with a computer system.

Software

The set of instructions the hardware executes to carry out specific tasks.

Computer

An electronic device operating under the control of instructions stored in its own memory that can accept, manipulate, and store data.

Central Processing Unit (CPU)

The actual hardware that interprets and executes the program (software) instructions and coordinates how all the other hardware devices work together.

Control Unit

Interprets software instructions and literally tells the other hardware devices what to do, based on the software instructions.

Arithmetic-Logic Unit (ALU)

Performs all arithmetic operations (for example, addition and subtraction) and all logic operations (such as sorting and comparing numbers).

Megahertz (MHz)

The number of millions of CPU cycles per second.

Gigahertz (GHz)

The number of billions of CPU cycles per second.

Complex Instruction Set Computer (CISC) Chip

Type of CPU that can recognize as many as 100 or more instructions, enough to carry out most computations directly.

Reduced Instruction Set Computer (RISC) Chip

Limits the number of instructions the CPU can execute to increase processing speed.

Primary Storage

Computer’s main memory, which consists of RAM, cache memory, and ROM that is directly accessible to the CPU.

Random Access Memory (RAM)

The computer’s primary working memory, in which program instructions and data are stored for direct access by the CPU.

Volatility

Refers to a device’s ability to function with or without power.

Volatile

Must have constant power to function; contents are lost when the computer’s electric supply fails.

Cache Memory

A small unit of ultra-fast memory that stores recently or frequently accessed data.

Read-Only Memory (ROM)

Portion of a computer’s primary storage that does not lose its contents when power is switched off.

Nonvolatile

Does not require constant power to function.

Flash Memory

A special type of rewritable ROM that is compact and portable.

Memory Cards

Contain high-capacity storage that holds data such as images, music, or text files.

Memory Sticks

Provide nonvolatile memory for portable devices including computers and cameras.

Secondary Storage

Consists of equipment designed to store large volumes of data for long-term storage.

Megabyte (MB)

Roughly 1 million bytes.

Gigabyte (GB)

Roughly 1 billion bytes.

Terabyte (TB)

Roughly 1 trillion bytes.

Magnetic Medium

A secondary storage medium that uses magnetic techniques to store and retrieve data.

Magnetic Tape

An older secondary storage medium using a strip of plastic coated with a magnetically sensitive recording medium.

Hard Drive

A secondary storage medium using several rigid disks coated with a magnetically sensitive material.

Solid State Drive

An all-electronic storage device that is faster than a hard disk.

Input Device

Equipment used to capture information and commands.

Stylus

A penlike device used to tap the screen to enter commands.

Output Device

Equipment used to see, hear, or otherwise accept the results of information processing.

Communication Device

Equipment used to send and receive information from one location to another.

Appliance

A computer dedicated to a single function, such as a calculator or game.

Ebook

An electronic book that can be read on a computer or special reading device.

System Software

Controls how various technology tools work together along with application software.

Operating System Software

Controls application software and manages how hardware devices work together.

Dual Boot

Provides the user with the option of choosing the operating system during startup.

Embedded Operating System

Used for a single purpose in computer appliances or special-purpose applications.

Multitasking

Allows more than one piece of software to be used at a time.

Utility Software

Provides additional functionality to the operating system.

Control Panel

A Windows feature that provides options to set default values for the operating system.

System Clock

Works like a wristwatch and keeps time even when the computer is turned off.

Safe Mode

Occurs if the system is failing and only essential parts of the operating system load.

System Restore

Enables a user to return to the previous operating system.

Application Software

Used for specific information processing needs.

Personal Information Management (PIM) Software

Handles contact information, appointments, and task lists.

Course Management Software

Contains course information and offers drop boxes for assignments.

Software Updates (Software Patch)

Occurs when the vendor releases updates to fix problems or enhance features.

Software Upgrade

Occurs when the vendor releases a new version of the software.

Single-User License

Restricts the use of the software to one user at a time.

Network User License

Enables anyone on the network to install and use the software.

Site License

Enables any qualified users within the organization to install the software.

Application Service Provider License

Software paid for on a license or usage basis.