1. Network devices 1-NIK 2- Hub 3- switch 4-bridge 5-router 6- modom

2. network interface card NIK network interface card NIK - provides the hardware interface between a computer and a network. It is network adapter hardware in the form factor of an add-in card such as a PCI card.PCI - Most NICs support either wired Ethernet or WiFi wireless standards..EthernetWiFi

4. من خلال nic يتعرف الجهاز على الشبكة ويتمكن من الاتصال ولها عدة وظائف رئيسية : 1-( وسيط بين الشبكة والجهاز ( نقل البيانات من الشبكة الى الجهاز والعكس ) 2- تحويل البيانات من الجريان بشكل متوازي (8 بت ) الى متسلسل (1 بت ) 3- تخفيف سرعة نقل البيانات من سرعة الجهاز الى سرعة الشبكة.

5. modem Convert data between the analog form used on telephone lines and the digital form used on computers. Standard dial- up network modems transmit data at a maximum rate of 56,000 bits per second (56 Kbps).Kbps Tow type: -internal -external

6. Hub الموزع Hub الموزع a device for connecting multiple devices together and making them act as a single network segment.network segment It has multiple input/output (I/O) ports, in which a signal introduced at the input of any port appears at the output of every port except the original incoming. A hub works at the physical layer (layer 1) of the OSI.input/outputsignalportphysical layerOSI

8. repeater A network repeater is a device used to expand the boundaries of a wired or wireless local area network (LAN). - The repeaters would amplify the data signals before sending them on to the uplinked segment.

9. - A repeater connects segments of a LAN. - A repeater forwards every frame; it has no filtering capability. A - repeater is a regenerator, not an amplifier.

10. switch - A is a telecommunication device that receives a message from any device connected to it and then transmits the message only to the device for which the message was meant. -This makes the switch a more intelligent device than a hub (which receives a message and then transmits it to all the other devices on its network)

12. الجسر bridge - connects two parts of a network together - - work similarly to network switches, but the traffic is managed differently. A bridge will only send traffic from one side to the other if it is going to a destination on the other side. - Since they need to look at the contents of the traffic going into them, they are much more complicated than a hub or repeater

13. A router - is a device that forwards data packets between computer networks, - - A router is connected two or more different networks. When a data packet comes, the router reads the address information in the packet to determine its destination. Then, using information in its routing table or routing policy, it directs the packet to the next network. - - Routers perform the "traffic directing" functions on the Internet. A data packet is typically forwarded from one router to another through the networks that constitute the internetwork until it reaches its destination node

14. router router - The most familiar type of routers are home and small office routers that simply pass data, such as web pages, email, IM, and videos between the home computers and the Internet. - More sophisticated routers,, connect large business or ISP networks up to the powerful core routers that forward data at high speed along the optical fiber lines of the Internet backbone.