So, what do we mean by the term affordances? This is a concept coined by the perceptual psychologist, James Gibson, to explain how we individually make sense of the world around us in terms of what movement and actions we are offered (afforded) by the environment in which we find ourselves. For each of us, these are unique, but many basic ones are shared because we share many experiences. We are also, as a species, attuned to pick up the same perceptual information (more or less). Different species will be attuned to different perceptual information and different affordances.
The more skilled a performer, the more they are attuned to the affordances that are available and ones that are specific to them as individuals. Affordances are perceived directly and much of our movement requires no conscious control.
Affordances change constantly because they are both about what information (perceptual) an individual is attending to, and what their current action capabilities are. Action capabilities, sometimes referred to effectivities, change due to skill acquisition, growth, injury, fatigue, motivation, intention, expectations, even hunger and dehydration.
James Gibson’s theory is known as Ecological Psychology.
These articles explore affordances in more detail:
Climbing.
Paddlesports.