Essential Computer Concepts
Describe the components of
a computer system
A computer system consists of much more than
just a computer; it also includes peripheral devices
The computer's physical components (such as the
main circuit board and the motherboard) are
referred to as hardware.
The peripheral devices are additional components
that are needed to accomplish input, output, and
Software refers to the intangible components of
the computer system, such as the programs that
the computer needs to perform specific tasks.
A typical computer with input
and output devices
This figure shows a
with some potential
input and output
Data is input, processed,
stored, and output
This figure shows a
typical processing cycle of
data. The user enters data
via the keyboard, it is
processed by the CPU, it
may be sent to another
workstation or to a
printer, and it is usually
saved on a storage device
Compare the types of
There are four basic types of computers:
These classifications are based on size,
speed, and cost.
Which type of computer is used
for what type of processing?
Microcomputers, or personal computers (PCs), come in several
Personal digital assistants (PDA)
Minicomputers are larger than microcomputers, and have the
capability of processing tasks for many users.
A mainframe computer is larger and more powerful than a
minicomputer and can handle many more users.
Typically used for centralized storage, processing, and data
The supercomputer is the largest and fastest of all the computers
and is used for high
volume computing tasks.
Typical microcomputer types
This figure shows the various
types of microcomputers
hardware in terms of input
and output devices
Many components can make up the hardware for a
microcomputer. Each type of component performs a
Input devices provide a method for inputting data and
Typical input devices include a keyboard, a mouse, or
another pointing device.
Output devices enable you to view the results of your
work and the processing work of the computer.
Typical output devices are monitors and printers
Typical input devices
This figure shows several devices used for inputting data to the computer
Other pointing devices
Define microcomputer hardware in
terms of processing and storage
Processing hardware is the most critical component of
a computer system.
It includes the microprocessor (a silicon chip designed
to manipulate data) and the memory that stores data
All of the data that is generated through your input or
the computer's processing needs to be stored in a
fashion that can later be retrieved.
This is done through storage devices and media, such
as magnetic storage devices (floppy disks and hard disk
drives), tape drives, and optical storage devices (CD
ROM and DVD drives).
Storage devices and RAM
Data is frequently
transferred from a
storage device to RAM
for processing, and
transferred back to the
storage device after
Store data on a magnetic
This figure shows
how data is stored on
a magnetic disk, be it
a hard drive or a
An optical storage device
This figure shows the
basic way in which
data is stored on an
optical storage device.
Examine data representation
and the ASCII code
A computer does not understand the characters
that are used in human languages.
A computer must represent every signal as
either “on” (with a 1) or “off” (with a 0).
These numbers are called binary digits or bits.
A series of 8 digits is called a byte.
How numbers appear in binary
This table shows how various
decimal numbers would be
represented in binary form
Note that each number
requires 8 bits, which
makes up one byte.
Learn about ASCII code
In ASCII code, which is commonly used by
microcomputers, each byte represents a unique
character (such as a letter, a number, or a
The storage capacity of the processor or
storage hardware is represented as the number
of bytes that the device can handle.
These capacities are expressed in kilobytes
(KB), megabytes (MB), or gigabytes (GB).
How letters and symbols
appear in ASCII code format
This figure shows how
several letters and symbols
would appear inside the
computer when converted
into ASCII format.
Note that each character still
requires one byte (8 bits) of
Describe how peripheral
devices are connected to a
In order for peripheral devices to be useful,
they must have a way of communicating data
with the microprocessor.
Each device has a port and a cable that
connects into the computer (either externally or
These ports connect to a controller card that
provides the electrical connection to the main
Microcomputers use ports
for input and output
There are several types of ports available with
Each has different capabilities for data
transmission, and each is designed to work with
different peripheral devices.
This figure shows the various types of
ports in use on modern microcomputers.
Notice that each port requires a different
9 Serial Port
25 Serial Port
Connect a printer to the
printer must be connected to a computer port before it can be used. It is connected
via a cable that has a connector on one end that fits into the printer port. The other
end has a connector that fits into the computer’s port.
Identify the hardware and software used
to establish a network connection
A network enables you to share data and resources
A typical network configuration is a local area network
(LAN), in which the computers and devices are located
relatively close to each other.
If a computer is connected to a network, it is referred
to as a workstation.
Each workstation requires a network interface card to create
the communications channel between the network and the
The computer workstation must also have network software to
establish communications protocols
Each device on the network is referred to as a node.
A typical LAN configuration
This figure shows a typical network with several workstations connected to a server,
and a printer connected to the network that can be accessed by any workstation.
Explain how Internet access, e
the World Wide Web affect
the use of computers
The Internet, which was originally developed for the government
to connect researchers around the world who needed to share
data, is the largest network in the world.
It can be used to send messages from one user's computer to
commonly called e
It can also be used to access the World Wide Web
database of information stored on network servers around the
You can use a Web browser to search for and view the
information available on any topic or to go to a specific location.
A Web page on the World Wide Web
The variety of text, images,
sounds, etc. that can be
displayed on the Internet, as
well as the format in which
they appear, is virtually
limitless. This figure is an
example of what one page of
one Web site looks like.
Discuss the types of system
software and their functions
The fundamental operations of your computer are
managed by the system's software.
There are four types of system software.
Operating system software controls basic input and output,
allocates system resources, manages storage space, maintains
security, and detects equipment failure
Utilities aid the operating system by taking over some of its
responsibility for allocating hardware resources
A device drive aids the computer in communicating with
individual peripheral devices
Computer programming languages are used by programmers
to write computer instructions
Software works with your hardware
to perform basic functions
Many of the components
of the system software
each other to assist you in
accomplishing your tasks.
This figure shows the
operating system software
working with the word
processing software in
order to print a document
Identify popular application
Application software (commonly referred to as
a computer program) enables you to perform
specific tasks with your computer.
Some typical tasks are: creating documents and
spreadsheets, managing databases, and
creating graphics and multimedia
All of these applications have features and tools
built into them that aid you in achieving the
best results for the project on which you are
Application software can be
purchased and installed
This figure shows
A word processing application
This figure shows a typical
window for a word
program. In this case, the
red line underneath the
word ‘bigin’ indicates a
potential spelling error that
was caught by the
A typical spreadsheet application
allow you to organize
data in a grid of rows
and columns. The
data can be used in
Use presentation software
allows you to create
slide shows that can be
shown via your
Describe how data is shared among
different types of application software
The ability to use data created in one application in
another application is one of the most powerful
developments in the software industry.
In the Windows environment, this is done through
object linking and embedding (OLE).
Embedding copies the source data from one application
into a different application.
The copy will remain in its new location regardless of what
happens to the original
Linking creates a continuous connection between
original source data and the copied data.
Whenever the source data is updated or changed, so too is the
data in the linked application