Since this section is not what the book is about, we will go through some basic protocols that we all have used (maybe without knowing). HTTP protocol is used when requesting a web page. For example, when someone types https://facebook.com/, he requests a web page called facebook. FTP protocol is used when a client connects in a file server. For example, when someone types ftp.ntua.gr/, he connects in a server where there are just files and no website or blog. In addition, TCP and UDP are protocols used for transmitting data. UDP is used for video call or voice call, where we need a huge amount of data transmitted, whereas, TCP is used for HTTP request or similar actions.

The reason we went through these protocols is because if you read further about them you will see that every single one of them has quite many bytes necessary to work properly, which means power over the cable, which in turn means energy consumption. So, people have thought that in Internet of Things we do not need the existing protocols and there are some new protocols specifically for IoT.