A compiler first takes in the entire program, checks for errors, compiles it and then executes it. Whereas, an interpreter does this line by line, so it takes one line, checks it for errors and then executes it.
Eg of Compiler - Java
Eg of Interpreter - PHP
Explanation 2:
interpretor translate the program line by line and compiler translate the entire program interpretor requires less memory and compiler requires more memory
definition of compiler:
Compiler is a program that translates a computer program written on one computer language to another computer language. A "compiler" is primarily used for programs that translate source code from a high level language to a lower level language (e.g., assembly language or machine language). A program that translates from a low level language to a higher level one is a decompiler. A compiler for a relatively simple language written by one person might be a single, monolithic, piece of software. When the source language is large and complex, and high quality output is required the design may be split into a number of relatively independent phases, or passes. Having separate phases means development can be parceled up into small parts and given to different people. It also becomes much easier to replace a single phase by an improved one, or to insert new phases later.
Interpreter is a program that translates an instruction into a machine language and executes it before proceeding to the next instruction..... A high-level programming language translator that translates and runs the program at the same time. It translates one program statement into machine language, executes it, and then proceeds to the next statement. This differs from regular executable programs that are presented to the computer as binary-coded instructions. Interpreted programs remain in the source language the programmer wrote in, which is human readable text. Interpreted programs run slower than their compiler counterparts. Whereas the compiler translates the entire program before it is run, interpreters translate a line at a time while the program is being run. However, it is very convenient to write an interpreted program, since a single line of code can be tested interactively.