Understanding Arithmetic Logic Unit (ALU)

The part of a computer that executes all
arithmetic and logical operations. The
ALU is one element of the Central
Processing Unit (CPU)

Understanding Computer

A programmable device that:

(1) Responds to a specific set of instructions
in a clear-cut manner.

(2) Executes a prepared list of instructions
(also called a program).

Modern computers are electronic plus digital.
The physical equipment--wires, transistors, and
circuits--is called hardware. The instructions
and data are called software.

Hardware Elements Found
In General-Purpose Computers

(1) Memory: Allows a computer to temporarily
retain data and programs.

(2) Mass Storage Device: Enables a computer
to permanently keep large amounts of data.

(3) Input Device: The channel through which
data and instructions enter a computer.
Usually constituted by a keyboard and mouse.

(4) Output Device: A display screen, printer,
or other device that enables a computer to
show what it has achieved.

(5) Central Processing Unit (CPU):
The brains of a computer. It interprets
and performs program instruction and also
coordinates the interaction of input, output,
and storage devices.

General Classification Of Computers
By Increasing Size And Power

Personal Computer: A computer used by
an individual at home, in the office, or on
the road. Also known as a microcomputer.

Workstation: A high-performance computer
with breakthrough graphics capabilities designed
for utilization by scientists and engineers.

Minicomputer: A midsize computer, sized
between a workstation (or microcomputer)
and a mainframe.

Mainframe: Generally the largest, fastest, and
most dear kind of computer, usually commanding
millions of dollars and requiring special cooling.
Mainframe computers can serve hundreds of
simultaneous users and normally are run around
the clock; typically they are possessed by
large companies.

Supercomputer: The fastest, biggest and most
expensive of the mainframe class of computers,
usually used for intricate scientific calculations.

General Classification Of Computers
By Increasing Size And Power

Personal Computer: A small, single user
computer based on a microprocessor.

Workstation: An able, single user computer.
A workstation is like a personal computer, but it
has a more powerful microprocessor and a
higher quality monitor.

Minicomputer: A multiuser computer capable of
supporting from ten to hundreds of
users simultaneously.

Mainframe: A powerful multiuser computer capable
of supporting many hundreds or thousands of
users simultaneously.

Supercomputer: An extremely fast computer that can
perform hundreds of millions of instructions per second.