Computer networks:

1. the computer network is a bunch of computers that are connected together with some wires
2. LAN: its your local area network for example the B and A computers are connected trough a switch and a router and all the things in your network like: router / switch / computers … others that are local we say them LAN
3. WAN : A wide area network (WAN) is a telecommunications network that extends over a large geographic area. Wide area networks are often established with leased telecommunication circuits.[1]
4. datacenter : is where that a lots of data is stored / and it is secured too

why we do need computer networks ?

we can share resources without using to run and give them the resource locally like the sneakers method because you need to use your sneakers to run and give them that resource (: / Files / programs / resources

firewall and IPS :

1. firewall : restricting the inbound and outbound connections
2. Next generation firewalls : allow for deep packet inspection / can utilize outside services to detect malicious attacks
3. IPS: intrusion prevention system : deeply inspecting packet’s and detecting the attacks

2tier and 3 tier and datacenter architecture: