The front-end is also referred to as the client-side and is sometimes considered "web design".
The back-end of the web industry is often called the server-side.
Language list here :https://www.quora.com/Which-programming-languages-are-front-end-and-which-ones-are-back-end
Back-end tier -> Databases and other data stores are generally at this level. Oracle, MS-SQL, MySQL, SAP, and various off-the-shelf pieces of software come to mind for this piece of software that is the final processing of the data.