Newbie Question

[Defratos]

Hello everyone, I am new to this forum and new to 3D printing. Recently bought a Bambulab X1 Carbon and have been playing around with it over the past few days. Mostly successful prints on easy models, but having a bit of difficulty when taking on more complex models with bed adhesion. I wanted to ask What is the main purpose of using glue on the bed? is it to help with the print adhering to the bed? or more to help with model removal at the end of the print?

Second Question, can I print without using any glue whatsoever?