What is the main difference between a compiler and an interpreter?

The distinction between a compiler and an interpreter is fundamentally rooted in how each processes source code. A compiler translates the entire source code of a program into machine code before any of it is executed. This means that the output of the compiler is a complete executable file that can be run independently of the original source code. This approach allows for optimizations that can enhance the performance of the program since the entire code can be analyzed at once before execution.

In contrast, an interpreter takes the source code and translates it line by line, executing each line immediately after it is translated. This means that the original source code must be available and the interpreter is actively converting it to machine code as it runs, which often leads to longer execution times compared to compiled code.

Understanding this difference is crucial, as it impacts aspects such as execution speed, error detection, and development workflow. Developers may choose to use one over the other based on specific needs, such as rapid testing and development with interpreters or optimizing performance in production with compilers.