Reached a HTB module that required me to have some prerequisite knowledge on networking basics so I enrolled to Cisco Networking Academy and hit the ground running. It thoroughly simplifies the basics giving you a firm foundation as you go along. This is what I've learnt so far:

Introduction to networking

We use networks to transfer and receive data. There are 3 types of data i.e. observed, volunteered and inferred which is generated by personal activities such as shopping online and the sites that we visit. Computers use binary language which is basically 1s or 0s. Each group of 8 bits is known as a byte.

Methods of data transmission

electric signals, optical signals and wireless signals.

Bandwidth refers to the capacity of a medium to carry data. Measured as the number of bits across the media in a second i.e. kbps, Mbps, gbps or tbps. Throughput refers to number of bits across the media over a period of time. Latency refers to amount of time data takes to travel from one point to another.

Clients and Servers

Host- all computers connected to a network participating in network communication.

Servers- Hosts that have software installed which enables them to provide information

Clients- Hosts that have software installed that enables them to request for information from servers. e.g Mozilla firefox, Chrome

Peer to peer networks

Refers to communication where by one host runs both a server and client software at the same time.

Peer to peer applications

Allows a device to act as both a client and server within the same communication

Every client is a server and every server is a client e.g. WhatsApp

Network Infrastructure

Refers to the platform that supports the network. It provides the stable and reliable channel over which comms occur. Categories are end devices, intermediate devices and network media. End Devices form interfaces that link the users and the underlying communication network. They are either the source or recipients of information. In order to uniquely identify hosts, addresses are used. When a host initiates communication, it uses the address of the destination host to specify where the message should be sent.