What is compilation error?

Question

and how do I solve it?

Answer 1

If the compiler is not able to understand the code, it results in an compilation error .Also the compiler points the line number and information about the error which helps in resolving it.
Based on the error you should be able to understand how to make it work.
If the error is complex , search for the error in Google to get some pointers on resolving it.

Answer 2

all syntax error will be detected By compiler

suppose if your missing semicolon the error categorized in compiler error .