A place to access a program, app, or website by which changes can be made by the owners. These changes will display on the customer facing side of the source, called the "front end".
The back end can be edited either by an interface designed specifically for the owners or by writing code. Back end actions are performed on the server that houses the site or program information and databases. The back end is not visible to customers which allows important business information to be stored there without sharing it with unintended parties.
Database, Front End