CCNA

Topics:
1.1- Network Definition
1.2- Network Importance
1.3- Network Components

Network:
It's a group of components or devices connected together to give
the users a certain services (applications). A network consists of
two or more computers that are linked in order to share resources
(such as printers and CD-ROMs), exchange files, or allow
electronic communications. The computers on a network may be
linked through cables, telephone lines, radio waves, satellites, or
infrared light beams.
Importance of network:
1- Easy sharing of files and information.
2- Sharing of expensive devices (servers and printers).
3- Modern techniques (VOIP, video conferencing,
net meeting).
Network components:
1- PC:
Source of network aware applications, we use some S/Ws loaded
on PCs and servers to made these network aware applications ex:
HTTP(Hyper Text transfere protocol) for browsing, FTP(File
transfere protocol), SMTP(Simple Mail Transfere Protocol) to send
mails, POP3(Post Office Protocol 3) to receive mails,Telnet
Application
2- Network devices:
Hub, modem, switch, router, repeater, NIC(Network Interface
Card), bridge.
3- Connectivity:
Cables – Wireless.