Symbolization is a technique that allows you to translate machine memory addresses to human-readable symbol information (symbols).
Why do we need to read what programs do anyways? We usually do not need to translate everything to a human-readable format when things run smoothly. But when things go south, we need to understand what is going on under the hood. Symbolization is needed by introspection tools like debuggers, profilers, core dumps, or any other program that needs to trace the execution of another program. While a target program is executing on a machine, these types of programs capture the stack traces of the program that is being executed.