I want to backup the home directory of my Mac. For reasons I won't go into, using builtin Mac backup tools is not an option and the backup cannot be too large. Luckily I already have my own software to do the backup, so the first point is taken care of. For the second point, I know that the data that is important would add up to about 5 GB, which acceptable.
When I took a look at my actual home directory however, it was way too big. It turned out that
~/Library alone takes about 50 GB.
What exactly is the purpose of this directory, and what sort of files are expected to be in it? What are the consequences of excluding it from the backup?