What is the Difference Between a Stand-Alone and Installed Executable File?

While most of us are content to go with the ‘tried and true’ process of installing the executable files for our favorite software, is it really necessary to do so? Could we actually extract those same executable files rather than install them, and run them the same as their stand-alone cousins via Pocket http://www.howtogeek.com/178409/what-is-the-difference-between-a-stand-alone-and-installed-executable-file/