What is the meaning of technology "affordances" and "constraints" in terms of education?

What are Affordances? Affordances is defined as "the qualities or properties of an object that define its possible uses or make clear how it can or should be used We sit or stand on a chair because those are fairly obvious" So, an affordance is often taken as a relation between an object, or an environment, and an organism that affords the opportunity for that organism to perform an action.Back in in 1988, Donald Norman basically put the word down as a human "machine interaction" 

So, for example, a button that is on a wall will need to be pushed. Or, a light switch needs to be flipped. If a car radio has a dial, then you will rotate the dial to the desired station. This article is a great read. It really goes into depth on affordances and constraints. It can be very helpful to someone like me who is just learning about it.

 
What is the definition of Constraints a constraint is basically a limit or restriction. The constraints are what keeps the affordances at a limit. It is the final product design for the final object. Merriam-Webster defines Constraint as "something that limits or restricts someone or something. Control that limits or restricts someone's actions or behavior"
At the end of the day, it is up to the teacher to help the students stay on track while they are using all of those resources. 

A site that can be helpful in the classroom is google slides