AusBonsai

I believe the term 'Crab' is from England and means wild, so crab-apple just indicates the tree is a self sown seedling and technically, any apple grown from seed is a crab apple.
We more often use the term for apples with smaller fruit. There are somewhere between 30 and 50 species of Malus and many of those have been used to breed the garden trees we now know as crab apples. Some of those species have different shaped leaves and some have different colored bark which may give some indication of a seedling being different from an eating apple but many are virtually identical until they flower or fruit. There is also a gradual change between the crab apples and domestic ones. Some crabs have relatively large fruit and some of the eating varieties have smaller fruit. I know some of the heritage eating apples have crab as part of the name indicating the origins as a seedling eg Huon Crab.
As you can see, the differences are not defined so it will usually be difficult to tell the difference, if there is any difference between crab apple and eating apple.

Thanks Neil, i now have a headache

Matthew wrote:I have one shohin crabapple ungrafted (florabinda ) that is the only one out of 20 I grew that became something . Crabapples in general are course in there ramification but mine is improving each year and I always wanted a shohin one . Watch hot summer days and they like a drink. Its one of the first trees to tell me when its thirsty

I found a older pic from 2016 . Tree has improved a lot since then ill have to get photos this spring . This I grew in the ground with several sacrifice branches lower to beef the trunk up . scars are now healed completely . has had 2 trunk chops in its time also . Ungrafted and the only one that played ball with me

Beautiful tree Matthew. Especially the trunk.