How do you use programming languages and scripting languages together?

Such a simple question, but I have not found a reasonable answer to this. I currently program in Python, an interpreted language. I always hear of people using multiple languages in the same program? Then I hear them using scripting languages; Can someone on here please in plain english explain to me the difference between what I know as programming languages and scripts, and how on Earth do people use multiple languages together. That just does not make any sense. How can someone use Javascript, PHP, and ASP together. Or program a game in C/C++ and use python as scripts? It just doesn't make sense to me, they are different languages for a reason, i assume, so how do they play a role with one another?