Affection is a feeling of liking and fondness for someone, it feels more personal than nurture and caring, which is a bit more distant and more about the person as a whole and their growth and safety and well-being. The latter can be more clinical.

Having said that, there is a lot of overlap and in a way it can be argued that affection is necessary to provide care and nurture that comes from a person's heart and is not just some clinical professional duty provided.

For me distinguishing them has been about the quality of care and nurture I have received, quality that made me sense the affection behind it all coming from a T. I'm an intuitive person and so it's not easy to point to what they say or how they acted but it's a combination of all of it that makes me sense there is affection there also.