What does a compiler do in C++ programming?

The role of a compiler in C++ programming is essential as it translates the source code written in C++ into executable machine code, which is a format that the computer's processor can understand and execute. This process involves several steps, including preprocessing, lexical analysis, syntax and semantic analysis, optimization, and code generation.

By converting high-level programming constructs into low-level machine instructions, the compiler enables developers to write code in a more understandable and manageable way, while still producing a program that runs efficiently on the hardware. This transformation is a critical step in software development, as it allows programmers to focus on logic and design rather than the intricacies of machine language.

In contrast, other options do not accurately represent the primary function of a compiler. While optimizing code for better performance is one of the processes that a compiler may perform, it is not the sole purpose. Additionally, compiling C++ code into HTML format or running code without changes does not reflect the actual function of a compiler in the context of programming languages like C++.