Pdb stands for Program Data Base.

The .pdb extension file is created to preserve the information needed to run your program in debug mode.

This file contains many important information needed when debugging Visual Studio.

With the help of .pdb files, the Visual Studio debugger can tell the line number of the code file where an error occurred in the stack trace.

"Debug Info" can be turned off if desired from the advanced (Advanced Build Settings) option in the release configuration (Build Settings).