Internet - WordPress.com

orangesvetElectronics - Devices

Nov 8, 2013 (4 years and 2 days ago)

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The

Internet

is

the

huge

network

of

computers

that

links

many

different

types

of

computers

all

over

the

world
.


It

is

a

network

of

networks

that

shares

common

mechanism

for

addressing

(identifying)

computers

and

a

common

set

of

communication

protocols

for

communications

between

two

computers

on

the

network
.


The

Internet

has

its

root

in

the

ARPANET

system

of

the

Advanced

Research

Project

Agency

of

the

U
.
S
.

Department

of

Defense
.


ARPANET

was

the

first

WAN

and

had

only

four

sites

in

1969
.


The

Internet

evolved

from

the

basic

ideas

of

ARPANET

for

interconnecting

computers

and

was

initially

used

by

research

organizations

and

universities

to

share

and

exchange

information
.


Personal

computers

or

terminals

were

connected

to

a

server
.


The

server

was

a

mainframe,

or

connected

to

a

mainframe

computer
.


The

mainframe

was

connected

to

another

mainframe

of

the

company

in

another

location

via

dedicated

lines
.


Only

large

companies

could

afford

the

expense

and

investment

in

equipment
.



In

1989
,

the

U
.
S
.

Govt
.

lifted

restrictions

on

the

use

of

the

internet

and

allowed

it

to

be

used

for

commercial

purposes

as

well
.


Since

then,

the

Internet

has

rapidly

grown

to

become

the

world’s

largest

network
.


Mainframes:


-

term for very large computers


-

used to handle large amount of data or


complex processes


-

main advantage is reliability


Midrange:


-

medium sized, less expensive and smaller


-

usually a server


Micro
-
computer:


-

work stations with computing capabilities


-

single
-
users systems linked to form a network


7


Series

of

points

or

nodes

interconnected

by

communication

paths


Node

is

a

connection

point

for

transmitting

data


Network

can

interconnect

with

other

networks

to

form

global

networks


8


Facilitates

resource

sharing


Provides

reliability


Cost

effective


Provide

a

powerful

medium

across

geographical

divid
e


1
0


Local

area

network

(LAN)
:

small

area,

share

a

single

server


Metropolitan

area

network

(MAN)
:

a

wider

network,

can

bridge

several

LAN’s


Wide

area

network

(WAN)
:

a

broader

area

covered,

can

include

several

MAN’s


Internet
:

a

network

of

networks

that

covers

the

entire

globe


1
2


Internet uses TCP/IP, therefore every computer on
the Internet has an IP address


IP address is numerical, separated by dots


Works with DNS:


-

com: for commercial purposes


-

net: for Internet Service Providers


-

org: for non
-
profit, non
-
commercial groups


-

gov
: reserved for government


-

mil: reserved for military


-

int
: reserved for international organizations


1
3


Technology

first

adopted

to

increase

efficiency



doing

the

same

tasks

faster

e
.
g
.

word

processing

instead

of

typing



Technology

next

adopted

to

increase

effectiveness



doing

tasks

not

only

faster

but

better

e
.
g
.

spreadsheets

transformed

finance

and

accounting

(as

well

as

science

and

other

fields)