There are at least 2 different definitions of affordances. The one I have experience with goes something like "affordances are things in the environment with which you can act". Some examples are door handles afford opening a door and walking through. Buttons, sliders, toggles, etc. afford various actions.

Affordances are what connect the screens of a given flow.

Some questions you can ask to determine whether you are affording a capability or not:

• Does this change affect whether a user can discover the feature?
• Does it clarify how to operate it?
• What am I helping them to do right now?

References

To learn more, see the work of:

Ryan Singer