Front-end is the design phase of the website using Javascript and Javascript frameworks like Jquery bootstrap, angular
Backend is the logic of the website, database handling, system scale, hashing passwords using Javascript Stack, Python, Ruby or Asp.net
Font end means where user work and visible to user. Back end means some work done here but does not visible to user.
Basically a tree is a font end and root is the back end of tree which does not visible to us.
