Date post: | 29-Mar-2015 |
Category: |
Documents |
Upload: | molly-grenfell |
View: | 222 times |
Download: | 2 times |
Chapter 1Chapter 1Introduction to Introduction to
ComputersComputers
Chapter 1Chapter 1Introduction to Introduction to
ComputersComputers
What Is a Computer?
What is a computer?• An electronic machine,
operating under the control of instructions stored in its own memory– accepts data– manipulates the data
according to specified rules
– produces results– stores the results for
future use
DataCollection of raw
unprocessed facts, figures, and symbols
InformationData that is organized,
meaningful, and useful
What are data and information?
What is a Computer?
Who is a user?• Someone that
communicates with a computer
• Someone who uses the information it generates
SoftwareThe series of
instructions that tells the hardware
how to perform tasks
HardwareThe electric,
electronic, and mechanical equipment
that makes up a computer
What are hardware and software?
InputAny data or
instructions you enter into a computer
OutputData that has
been processed into informationStorage
Area in a computer that can hold data
and information for future use
CommunicationThe capability of communicating
with other computers
What is the information processing cycle?
What is a Computer?Process
Manipulate the input (data) to
produce output (information)
What are common computer hardware components?
printer
scanner
speakerPC camera
microphonedigital camera
system unit
keyboard
modem
speaker
monitor
mouse
What is an input device?
• Any hardware component that allows a user to enter data and instructions into a computer
scanner
microphone
keyboard
mouse
PC camera
digital camera
What is an output device?
• Any hardware component that can convey information to a user
printer
monitor speakers
What is the system unit ?
• Sometimes called a chassis
• A box-like case made from metal or plastic that protects the internal electronic components of the computer from damage
• Circuitry in the system unit usually is part of or is connected to a circuit board called the motherboard
hard disk drive
CD-RW drive
CD-ROM or DVD-ROM drive
Zip® disk drive floppy
disk drive
What is a chip?
• An electronic device that contains many microscopic pathways that carry electrical currents
Usually no bigger than one-half inch square
Packaged so it can be attached to a motherboard
processor chip packaging
memory chip
What is a floppy disk?
• A thin, circular, flexible disk enclosed in a plastic shell
• Insert and remove a floppy disk into and from a floppy disk drive
• A Zip® disk is a higher capacity disk
What is a hard disk?
• Consists of several circular platters that store items electronically
• Disks are enclosed in an airtight, sealed case, which often is housed inside the system unit
• Provides much greater storage capacity than a floppy disk
• Some hard disks are removable
removable hard disk
self-contained hard disk
What is a compact disc?
• A flat, round portable medium that stores data using microscopic pits, which are created by a laser light – CD-ROM– CD-RW
• rewriteable CD
– DVD-ROM • tremendous storage
capacities
What is a communications device?
• Enables computer users to communicate and to exchange items such as data, instructions, and information with another computer
• Allows you to establish a connection between two computers and transmit items over transmission media, such as cables, telephone lines, or satellites
modem
One type is a modem
SpeedBillions of
operations can be carried out
in a single second
Why Is a Computer So Powerful?
What characteristics make a computer powerful?
Storage
Enormous amounts of data can be stored and
made available for processing anytime it is
needed
Reliability
Dependable because components have a low failure rate so
they produce consistent results
Accuracy
If data is entered correctly and program works properly, the results are error-free —
garbage in, garbage out (GIGO) accuracy of output depends on accuracy of
input
Communications
Two connected computers can share
stored data, instructions, and information