.exe
In WinDos it is .exe, in Unix executables usually have no extensions.
executable program
The main Excel program file (excel.exe) is an executable file, but the workbooks it creates are not executable files.
Executable means that the file has a series of instructions used to execute a program. Non-executable files are ones that do not have these instructions.
Program file extensions simply identify the type of program. For example, an executable program will have a file extension of .exe, and some music files will have the file extension of .mp3
Process is the program in the running state and program is a set of code un-executed, saved in a file. 1 program can produce 1 or many processes
There are several possible reasons, but the most common is that the computer operating system doesn't recognise the file is an executable program.
Easy to organise and maintain your project. Application extensions can be reused for multiple projects. A program with a class library will run much faster than one with all the code in the main executable.
Compile and link it into an executable.
linker or binder
You can run a program in any OS. For example an executable program can be run in windows by .exe file extension.
Putting '.exe' after a file name means that it is an executable file. This means that it is a program that can run by its self. So, yes, exe does represent an executable file.