Today people have lots of files and photos, movies , which can be on various computers.
Being able to share them between all your computers or devices from a central location is possible, either via a dedicated Server or by having a NAS (Network-
A NAS is a hardware enclosure that consists of at least one hard drive, an operating system and connected to your network via your router, the device acts as an external hard drive that's accessible from every computer on your network. Most wireless devices can be connected as well and will be able to access the NAS. The NAS is a excellent location to do backups.
An example of a typical NAS layout: