If you have Macs your current network solution is likely to include a Mac mini, or even an XServe, configured with additional Server Apps from the App Store to enable functions such as file sharing and permissions etc.
The big issue with this is that since the old OSX server upgrade to the new version of MacOS High Sierra came into effect and server functionality has been severely reduced as Apple pull back support for Servers and push towards Cloud only Servers.
Apple have also removed FTP and iOS File sharing from the Server App, which means that it is no longer a network manager, and has become more like the office junior/filing assistant. When you combine this with the fact that the Mac Mini tech is now getting fairly old, with it not having been updated since late 2014, plus that it’s missing important items such as Thunderbolt 3, and it becomes clear that the functionality has reduced to the point of being almost useless. Which, let’s face it, is not a great deal of use to most businesses!