What role does a compiler play in programming?

A compiler serves a crucial role in the programming process by transforming the entire source code written by a programmer into machine language, which is executable by the computer. When a programmer writes source code in a high-level programming language, it is not directly understood by the computer's processor. The compiler processes this code, performing several key functions.

First, it checks the code for syntax and semantic errors, which helps ensure that the program is written correctly according to the rules of the programming language. This error-checking is critical, as it allows the programmer to identify and fix issues before the program is run.

Next, once the code is error-free, the compiler translates the entire program into machine language in one go. This results in a compiled program that can be executed directly, which often leads to improved performance compared to interpreted code, which is executed line by line.

The other options, while related to programming, do not accurately represent the primary function of a compiler. For example, executing the program line by line is characteristic of an interpreter, not a compiler. Although debugging can occur during the compilation process, that is just one aspect of what a compiler does—it does much more by also producing the final executable code.