The compiler can locate and describe syntax errors.

The linker can reveal the existence of inconsistencies among program components and give some help as to how to locate them.

Runtime errors are logical errors that can exist in a program that is syntactically correct and contains no undefined objects or functions.

A debugger permits the stepwise execution of your code and the inspection of object values.

The GNU family of developer tools includes gdb, the source-level GNU debugger, which you can use for C/C++ applications.

gdb has been designed with a command-line interface that is quite powerful but not particularly user-friendly.

Commercial C++ IDEs (e.g., Visual Studio) generally have built-in source-level debuggers.