Words, phrases and abbreviations people use on the internet is called netspeak. It can also be called internet slag.
Netspeak is the casual and informal language some internet users use when communicating online. It is full of acronyms and abbreviations, symbols, emoticons and emoji, and slang. It started in the early days of the internet and its use has continued. Over time netspeak has evolved, driven by memes, trends and the desire to connect with others who 'get it.'