Open manually; may be referenced by an application
★ ★ ★ ★ ☆ Common
A PCH file contains source code that is referenced by a programming project before it is compiled. It often links to other files, using #import and #include commands.
PCH files are used by several different programming applications, including Apple Xcode and Microsoft Visual C++. They are often included with the programming software and can be opened with a text editor. However, they typically should not be modified by the user.