On Windows 10, using gcc and the "Power Shell":
PS C:\Source>gcc sumVersion1.c PS C:\Source>a sum: 55 PS C:\Source>
Comments:
This code is pretty much standard.
Nothing should be a surprise, here.
The source file is compiled and linked to form the executable file a.exe
which can be run by entering "a" at the prompt.
Linux and Apple shells will work the same.
You may have to enter ./a.out or similar depending on your system.