$2\mathrm{.}1$ A peripheral is anything connected to a computer, like a keyboard, mouse, printer, etc.

$2\mathrm{.}2$ The system unit is the core of a computer system.

$2\mathrm{.}3$ Hertz $($Hz$)$ as a unit is defined as the number of cycles per minute.

$2\mathrm{.}4$ The CPU is usually an integrated circuit called a microprocessor, which carries out the functions of retrieving, decoding, carrying out, and writing back.

$2\mathrm{.}5$ RAM is the permanent storage device within a computer system.

$2\mathrm{.}6$ Inkjet printers can produce high quality photographs when used with special paper.

$2\mathrm{.}7$ Laser printers are the slowest type of printers available.

$2\mathrm{.}8$ A modem sends and receives computer information over a telephone line or high$-$speed cable.

$2\mathrm{.}9$ CPU stands for Central Performance Unit.

$2\mathrm{.}10$ A microphone is used an input device.

$2\mathrm{.}11$ CD stands for collective disk

$2\mathrm{.}12$ Software is soft to touch.

$2\mathrm{.}13$ Only certain computers require software.

$2\mathrm{.}14$ The microprocessor is the device in the computer that performs most of the tasks we ask the computer to do$.$

$2\mathrm{.}15$ ROM can be written to$.$

$2\mathrm{.}16$ Secondary storage is sometimes contained in the CPU

$2\mathrm{.}17$ The two major types of software are programming languages and applications.

$2\mathrm{.}18$ A computer is a device capable of performing computations and making logical decisions at speeds millions $($even billions$)$ of times faster than human beings can.

$2\mathrm{.}19$ in the information processing cycle, the processor uses ram as the temporary working area to manipulate the data.

$2\mathrm{.}20$ Communication hardware devices enable computers to communicate with other computers and devices.