Question

What is Front - End and Back - End ?

Answer 1

If you're referring to is the front- or back-end of software, commonly the front-end is the client side (what the user interacts with), and the back-end is the server side. A web browser is front-end, the web-server itself is back-end.

Answer 2

"Front end and back end are generalized terms that refer to the initial and the end stages of a process" http://en.wikipedia.org/wiki/Front_and_back_ends.

For example a compiler it can be divide in stages (it have tons more):

preprocessor -> parser -> intermadiate code ->optimized intermadiate code -> machine code

here u can break this in two programs two: a front end and a back end(in wikipedia u will see its in 3, but u can do in 2 too, i just want to point ur question).

the first one will generate the optimazed intermadiate code
the second one the machine code

its like u have two things and the output of one its the input of the other one. In this example it makes totally sense, the front end will allways generate a code that the back end can read ats it input, so it makes designing program a lot easier.

gcc its done in this way( http://en.wikipedia.org/wiki/GNU_Compiler_Collection). So if u want to write a new lenguage u just make an front end and use gcc for the rest, its quite more easy, u just have to do a little part of the work and use something already created and tested.