Each of your document libraries likely includes documents that are more important or referred to more frequently than others. To ensure you and your team get quick access to these documents, you can pin them at the top of your document library.
This means that — regardless of the file name — they will be at the top of the list, and will be the first files you see when you go into the library.
To do this, simply right-click on the file or folder you want to pin and select “pin to top” from the dropdown menu.