What is the difference in some in flight meal options?

Baby meals are usually little jars of pureed baby food. Apple and Banana flavours or similar...

Child meals are usually chicken nuggets, or fish fingers, and it is usually prepared so it looks like a clown face, or something else that is equally appealing to young children.

As for toddler meals, I have never heard of them before, so I can't really tell you for sure. The airline I flew for didn't have them. But I can only guess that it is designed for very young children.

All child meals are usually very bland, as most children are fussy eaters, and don't like to eat anything with flavours they don't recognise.