GIF Version.
Having worked in two institutos and two colegios here in Spain, I feel very qualified to write this post. When you work in a colegio, you are godlike. The kids may draw pictures of you, write you love notes, bring you presents, pick flowers for you out on the playground … you get the picture. When you work in an instituto, not so much. You are most likely seen as a welcome distraction from the day-to-day monotony of regular English class. But it’s also possible they think you’re, like, totally lame. (You got me.)
So what’s the difference, anyway?
When you want to play a game
Colegio (Elementary):
Instituto (High School):