I'm not sure if everyone actually understands the whole point of libraries or not.
A library will let you be able to have all your say "documents", or whatever, folders that are saved at different locations (local or network) to be
included (referenced/indexed) in the library so you can access all files in all these different folder locations in the one central library location instead with all the files still saved at the different folder locations. This way you do not have to go to each different folder to change, delete, open, etc... a file. You can do it all from within the library instead.
If you have certain files of the same type saved in different folders across your local and/or network(s), then having them included in a library can make it much easier to keep track of all these files in the one library location versus each different folder location.
That's all.