Hello moni5550,
Those words like "brb and lol " are abbreviations called texting or short language .It is part of the English Netspeak, those words are only used for online chat on the net.They are used globally whether you are typing English or any other language.If you are writing in Spanish you will still express your laugh with "lol" etc...
Other than that there are some Spanish abbreviations that Spanish and Latin people use.
They can tell you more about it ;)