Switch: provides full duplex communication. It is intelligent because it allows two way communication.
Bridges: Helps my computer and the network connect to each other. It creates a path.
Firewalls: Lets some information in and keeps other information out. Accept information (allowing traffic), reject information (blocking trafic and reporting) or drop information (blocking traffic without giving a message).
Gateways: Helps block unnecessary data that will come and hamper your system.
Servers
OSI: Open system interconnection. First ever structur for web communication between any two devices. There are 7 layers.
7 server layers.
A network engineer will work on the layers 2–7.
Application layer: produces data.
Presentation Layer: Translation layer. Encrypts and decrypts.