In Vitro vs. In Vivo

While reading, I came across the terms "in vivo" and "in vitro".  Because I was in a hurry, I just skimmed past them, assuming that they were the same thing. It wasn't until I was four pages in that I realized that I was completely lost, and that these latin terms have completely opposite meanings. Here is an important distinction:

In vivo: (Latin for "within the living") This term is referring to the body as a whole, in that it is the larger, inclusive processes in the body. 

In vitro: (Latin for "within the glass") When you take anything out of the body or the context of the body it becomes in vitro. This would be something like cell biology or culturing in a petri dish. 

To sum up, 

In vivo fertilization: "Ay babe, let's have sum sex so we can make dat bay-bay."

In vitro fertilization: "Ay babe, let's takea few of doze eggs outta dat body and fertilize dem wit sperm inna test tube.... gurl."