Compile Time refers to the phase in programming when source code is translated into machine code by a compiler. This process checks for syntax errors and ensures that the code adheres to the rules of the programming language. If any issues are found, the compiler generates error messages, allowing developers to fix them before the program runs. During Compile Time, optimizations can also be applied to improve the efficiency of the final executable. This means that the code is not only checked for correctness but also refined for better performance. Once this phase is complete, the program can be executed without further compilation.