What is an inter-library loan and why might you use it?

If you want to read something and it is not in the library that you are at but it is in another library let's say clear across the country then you ask for a inter-library loan and they get the book or material you are asking for and it is sent to your library.

I do family history and sometimes someone has published a book on parts of my extented family in a form of a history book. I can ask the library to get the book for me. I can't check the book out because it is a Reference book but I have ample time to read it and copy what I need out of the book. Then they keep it at my library until I have finished it then they return it to the original library.What is an inter-library loan and why might you use it?If you need a specific book to do your homework and your library doesn't have it, they can look up to find out which other libraries have it. Then they can choose another library (preferably not too far away) and ask to borrow the book from the other library, so then they can let you read it. That's an inter-library loan.