Alright, before starting to learn specific skills about Windows Server . You need some basic understandings in  Networking fundamental.

If you've been through this before, you can skip it, but make sure that you have a glance to know what it is .

I) Network Topology : 

Network Topology is kind of shape of Network in your house, your office or your school .

1/ Token Ring : 



As its name says : all computers connect to a "Ring". If the ring is broken somewhere,  computer cannot communicate with each other .
Just one computer can send data at a time .
Data are sent one-way (clockwise or counter clockwise)
Use method called "Token Passing" - it means if a computer want to send data, it needs a token (like a priority) , taken from other computers .
So, data transfer speed is slow ~ 10 Mbps
=> This Topology is oblivion .

2/ Bus :



The two end-points are called Terminators .
Computers connect to the Bus by T-connector .
If computer 1 want to send data to computer 4, data must be send to computer 2, computer 3 ... => Not assure for security .
If 2 computers are sending data simultaneously - bandwidth is divided by 2 and  so forth .
This topology is easy to expand (just connect a computer to the Bus)
Because of slow speed, it is no longer used in modern Network.


3/ Star :
There is always a central device (called HUB - in this figure) .
Every computer becomes a member by connecting to central device .
Speed : 100 Mbps
Easy to deploy and expand .

=> The most popular Network topology is used nowaday .

There're also many topologies, but we just focus on the main ones ; you can find out more about them by doing some Google searches.

II) Network Devices :

1)  Network Interface Card (NIC) - or Network Adapter :

- It's a part of your computer (behind a CPU-Case)
- Help computers to communicate to each other, and connect to central device - also .
- To recognise each other, NIC has something called : Address . Imagine that NIC is a house - if I need to send email to you - I need your House's address, right ?
- NIC has 2 types of address :
+  Physical address (MAC address) : Producer provides and cannot be changed - It's unique .
+ Logical address (Netowork address - IP address) : can be changed by administrator .


2/ Central devices :

Today,  Hub is no longer used; instead , we use Switch which provides more efficient functions and enhance speed of transfer, also .

Central devices are used in Star Topology as I wrote in previous section.



3/ Cable :

2 types of cable :
- UTP : Unshielded Twisted Pair . Cheap.


- STP : Shielded Twisted  Pair . Cover by copper to avoid interferences . Expensive 3 times when compare to UTP cable .

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