The back end of a website is everything that goes on behind the scenes, from servers to databases, and much more.
In a nutshell, a website’s back end is everything the user doesn’t see. It is the beating heart, or the churning engine of a website — responding to requests made by the user by sending information from the back end to the front end to be displayed.
The back end of a website comprises things like servers, databases, operating systems, APIs, and more, all of which come together to ensure that the user is served with the correct information as quickly as possible.
While all website front ends (the visual stuff users actually interact with) are very different, back ends are often quite similar. Most websites will feature a back end stack made up of several key elements, including:
The server, which is the physical disk on which the website’s data is stored. Essentially an enormous hard drive, servers are often located in huge ‘farms’ and make up the physical side of the internet.
The database, which is the storage methodology for a site’s data. Databases can be queried to fetch and return information on-demand to be displayed by the front end. The most common database format is MySQL.
The API, or Application Programming Interface, is almost like a filter through which third-parties can access information from a database. This allows developers to use other website’s data — like social media posts, for example — in their own apps.