What is the difference between compiler and interpreter?

Not much but a compiler takes high level code and converts it to machine language (0's and 1's). An interpreter takes a command line (usually in a script) and converts it to a system operation. Interpreters (and script based languages like Python, Ruby, and Perl) are faster then Compilers but they are limited to what they can do (for instance you can't create a new system operation with them).