App, Program, Software, Script, Process

Believe this is the most concise description I have seen.

  1. An app is complete set of functionality like a game
  2. A program is a piece of or whole of an app
  3. Programs are written with software
  4. Software is written with scripts or any one or more of various programming languages (please see my answer here: Jack Menendez's answer to In layman's terms, what are the major programming languages, and what are they used for?)
  5. A process is an isolated instance of a program running in a computer.

From: What is the difference between a program, an app, a software, a script, and a process? on Quora, question by Luca Dorigo, answer by Jack Menendez.