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A compiler takes the source code as a whole and translates it into machine code all in one go. Once converted, the machine code can be run at any time. This process is called compilation.


An interpreter translates source code into machine code one instruction at a time. It is similar to a human translator translating what a person says into another language, sentence by sentence, as they speak. 


Assemblers are a third type of translator. The purpose of an assembler is to translate assembly language into machine code. Whereas compilers and interpreters generate many machine code instructions for each high-level instruction, assemblers create one machine code instruction for each assembly instruction. (Read more in the BBC Bitesize article below)

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