[ Computer Network ]
[ Unit 1 ]
[ Introduction to Computer Network ]
A computer network is a system that connects numerous independent
computers in order to share information (data) and resources. The integration of
computers and other different devices allows users to communicate more easily.
A computer network is a collection of two or more computer systems that are
linked together. A network connection can be established using either cable or
wireless media. Hardware and software are used to connect computers and tools in
any network.
A computer network consists of various kinds of nodes. Servers, networking
hardware, personal computers, and other specialized or general-purpose hosts can
all be nodes in a computer network. Hostnames and network addresses are used to
identify them.
Goal Of Networking :
Programs do not have to execute on a single system because of resource and
load sharing.
Reduced costs – Multiple machines can share printers, tape drives, and
other peripherals.
Reliability – If one machine fails, another can take its place.
Scalability (it’s simple to add more processors or computers)
Communication and mail (people living apart can work together)
Information Access (remote information access, access to the internet, e-
mail, video conferencing, and online shopping)
Entertainment that is interactive (online games, videos, etc.)
Social Networking
, [ Types of Networks ] :
Division based on the communication medium :
Wired Network: As we all know, “wired” refers to any physical medium made up
of cables. Copper wire, twisted pair, or fiber optic cables are all options. A
wired network employs wires to link devices to the Internet or another network,
such as laptops or desktop PCs.
Wireless Network: “Wireless” means without wire, media that is made up of
electromagnetic waves (EM Waves) or infrared waves. Antennas or sensors will
be present on all wireless devices. Cellular phones, wireless sensors, TV
remotes, satellite disc receivers, and laptops with WLAN cards are all examples
of wireless devices. For data or voice communication, a wireless network uses
radio frequency waves rather than wires.
Division based on area covered :
Local Area Network (LAN): A LAN is a network that covers an area of around
10 kilometers. For example, a college network or an office network. Depending
upon the needs of the organization, a LAN can be a single office, building, or
Campus. We can have two PCs and one printer in-home office or it can extend
throughout a company and include audio and video devices. Each host in LAN has
an identifier, an address that defines hists in LAN. A packet sent by the host
to another host carries both the source host’s and the destination host’s
address.
Metropolitan Area Network (MAN): MAN refers to a network that covers an
entire city. For example: consider the cable television network.
Wide Area Network (WAN): WAN refers to a network that connects
countries or continents. For example, the Internet allows users to access a
distributed system called www from anywhere around the globe.WAN
interconnects connecting devices such as switches, routers, or modems. A LAN
is normally privately owned by an organization that uses it. We see two distinct
examples of WANs today: point-to-point WANs and Switched WANs
Point To Point: Connects two connecting devices through transmission
media.
,Switched: A switched WAN is a network with more than two ends.
, [ Based on the type of architecture ] :
P2P Networks: Computers with similar capabilities and configurations are
referred to as peers.
“Peer to Peer” is the abbreviation for “peer to peer.” The “peers” in a peer-to-
peer network are computer systems that are connected to each other over the
Internet. Without the use of a central server, files can be shared directly
between systems on the network.
Client-Server Networks: Each computer or process on the network is either a
client or a server in a client-server architecture (client/server). The client asks
for services from the server, which the server provides. Servers are high-
performance computers or processes that manage disc drives (file servers),
printers (print servers), or network traffic (network servers)
Hybrid Networks: The hybrid model refers to a network that uses a
combination of client-server and peer-to-peer architecture. Eg: Torrent.
[ Unit 1 ]
[ Introduction to Computer Network ]
A computer network is a system that connects numerous independent
computers in order to share information (data) and resources. The integration of
computers and other different devices allows users to communicate more easily.
A computer network is a collection of two or more computer systems that are
linked together. A network connection can be established using either cable or
wireless media. Hardware and software are used to connect computers and tools in
any network.
A computer network consists of various kinds of nodes. Servers, networking
hardware, personal computers, and other specialized or general-purpose hosts can
all be nodes in a computer network. Hostnames and network addresses are used to
identify them.
Goal Of Networking :
Programs do not have to execute on a single system because of resource and
load sharing.
Reduced costs – Multiple machines can share printers, tape drives, and
other peripherals.
Reliability – If one machine fails, another can take its place.
Scalability (it’s simple to add more processors or computers)
Communication and mail (people living apart can work together)
Information Access (remote information access, access to the internet, e-
mail, video conferencing, and online shopping)
Entertainment that is interactive (online games, videos, etc.)
Social Networking
, [ Types of Networks ] :
Division based on the communication medium :
Wired Network: As we all know, “wired” refers to any physical medium made up
of cables. Copper wire, twisted pair, or fiber optic cables are all options. A
wired network employs wires to link devices to the Internet or another network,
such as laptops or desktop PCs.
Wireless Network: “Wireless” means without wire, media that is made up of
electromagnetic waves (EM Waves) or infrared waves. Antennas or sensors will
be present on all wireless devices. Cellular phones, wireless sensors, TV
remotes, satellite disc receivers, and laptops with WLAN cards are all examples
of wireless devices. For data or voice communication, a wireless network uses
radio frequency waves rather than wires.
Division based on area covered :
Local Area Network (LAN): A LAN is a network that covers an area of around
10 kilometers. For example, a college network or an office network. Depending
upon the needs of the organization, a LAN can be a single office, building, or
Campus. We can have two PCs and one printer in-home office or it can extend
throughout a company and include audio and video devices. Each host in LAN has
an identifier, an address that defines hists in LAN. A packet sent by the host
to another host carries both the source host’s and the destination host’s
address.
Metropolitan Area Network (MAN): MAN refers to a network that covers an
entire city. For example: consider the cable television network.
Wide Area Network (WAN): WAN refers to a network that connects
countries or continents. For example, the Internet allows users to access a
distributed system called www from anywhere around the globe.WAN
interconnects connecting devices such as switches, routers, or modems. A LAN
is normally privately owned by an organization that uses it. We see two distinct
examples of WANs today: point-to-point WANs and Switched WANs
Point To Point: Connects two connecting devices through transmission
media.
,Switched: A switched WAN is a network with more than two ends.
, [ Based on the type of architecture ] :
P2P Networks: Computers with similar capabilities and configurations are
referred to as peers.
“Peer to Peer” is the abbreviation for “peer to peer.” The “peers” in a peer-to-
peer network are computer systems that are connected to each other over the
Internet. Without the use of a central server, files can be shared directly
between systems on the network.
Client-Server Networks: Each computer or process on the network is either a
client or a server in a client-server architecture (client/server). The client asks
for services from the server, which the server provides. Servers are high-
performance computers or processes that manage disc drives (file servers),
printers (print servers), or network traffic (network servers)
Hybrid Networks: The hybrid model refers to a network that uses a
combination of client-server and peer-to-peer architecture. Eg: Torrent.
