Key Difference: Interpreters translate high level programming instructions into intermediate codes and then execute the resulting codes. Compilers translate high level programming language codes into the object codes. Interpreters execute code line by line, whereas compilers execute the resulting files.

Interpreter and Compiler play a very important role in execution of programs in a computer language. Many people tend to think that both of them are similar to each other. However, they both differ in various contexts.

We can only communicate with computers in their language. Computers only understand the binary language of 0’s and 1’s. However, most of the programs are written in high languages and thus, needs to be translated in the binary form. Interpreter and compiler are both programs which translate the language of programs into computer understandable machine language. You might think that both are serving the same purpose then how they both are different to each other.

The biggest difference between the two is that a compiler directly changes the source code into the machine language, whereas an interpreter produces a middle code and then executes this code in order to form a machine understandable code. Interpreters and compilers have same task of translating the source code into the machine code, but they differ in the means of achieving this translation. Compliers possess diagnostic capabilities and thus, while compiling a high level program they can prompt  appropriate error messages. In the case of an interpreter, object code is not stored and thus, cannot be reused.

A compiler produces an object code before creating an executable file for the same. The compiled program is directly executed using the object code. On the other hand, an interpreter executes the source code by reading one line at a time. During the time of execution, the native code is performed line by line. Both compilers and interpreters are written in high level programming languages. For example, a java interpreter can be written in Java, Pascal, etc. Both have their own set of advantages and disadvantages. Both the approaches can be mixed to attain a hybrid approach. For example, in LISP language, development is done in a LISP interpreted environment. The resulting modules are then well tested and can be compiled by the LISP compiler. The differences are listed below in the table:-

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