Does Time Machine back up my entire HD?

Am completely new to Mac, and a small issue its happening and Apple wants me to clear my VRAM. Been in this business long enough to know how quickly things can go south, and I have a lot of work on this Mac, including a lot of purchased software licenses.

So my question is this:

If I run Time Machine on my Mac, will I have a complete restorable copy of everything just in case my Mac somehow returns to factory settings or worse?

Thank you