Absolute and Relative Effects

https://www.etcconnect.com/Support/Tutorials/Eos-Family-Videos/Level-2-Enhanced.aspx

These trainings give several examples of these types of effects.  Relative effects are great if you need to make a specific shape or movement, but don't need to hit a specific point.   

If the light needs to reach a specific destination on the stage, then Absolute effects are your friend, as you can point the fixture to a specific location using focus palettes.  

https://www.etcconnect.com/Support/Tutorials/Eos-Family-Videos/Level-2-Enhanced.aspx

These trainings give several examples of these types of effects.  Relative effects are great if you need to make a specific shape or movement, but don't need to hit a specific point.   

If the light needs to reach a specific destination on the stage, then Absolute effects are your friend, as you can point the fixture to a specific location using focus palettes.  

Aha. Yes, I've been plowing through those very videos but like most of them they go very fast and in most cases are already using groups and palettes already set up. Sometimes I have to go back and run a bit over and over to understand an important word. And, I find the videos are mainly demos setting stuff up. I was after something more like your reply  I.E. The philosophy behind choosing these different methods. Definitely not knocking the videos here. More like my lack of experience.

Thanks Sara