Compilation and interpretation are two ways that programming languages are converted into machine code, which computers can understand.

**Compilation** is the process where a complete program is translated from a high-level programming language (like C or C++) into machine code all at once, creating an executable file. This file can be run directly by the computer. The compiler checks the entire code for errors before creating the executable. Once compiled, the program runs faster because the machine code is already prepared.

**Interpretation**, on the other hand, translates the program line by line or statement by statement at runtime. An interpreter reads the source code of a programming language (like Python or JavaScript) and executes it immediately, without creating a separate executable file. This means it can be more flexible and easier to debug since you can test parts of the code without compiling the whole program. However, interpreted programs usually run slower than compiled ones because the translation happens on the fly.

In summary, compilation translates the entire program at once, creating a separate file that runs faster, while interpretation translates and runs the program line by line, which is more flexible but can be slower.