How does an interpreter/compiler work

Question

How does an interpreter/compiler work? What is the difference between interpreter and compiler.

Answer 1

From Compilers and Interpreters

Compilers

Compilers were the first sort of translator program to be written. The idea is simple: You write the program, then hand it to the compiler which translates it. Then you run the result.

Interpreters

An interpreter is also a program that translates a high-level language into a low-level one, but it does it at the moment the program is run. You write the program using a text editor or something similar, and then instruct the interpreter to run the program. It takes the program, one line at a time, and translates each line before running it: It translates the first line and runs it, then translates the second line and runs it etc.

From Compiler vs. Interpreter

Compiler characteristics:

• spends a lot of time analyzing and processing the program
• the resulting executable is some form of machine- specific binary code
• the computer hardware interprets (executes) the resulting code
• program execution is fast

Interpreter characteristics:

• relatively little time is spent analyzing and processing the program
• the resulting code is some sort of intermediate code
• the resulting code is interpreted by another program
• program execution is relatively slow

Answer 2

Compiler, transforms source code in one computer language to another one.

Interpreter, executes source code directly (usually inside its own virtual machine).

Generally interpreter is performance costly.