What I learned from articles I read from cooking websites on the internet is that the word to roast is associated more with meat and vegetables, whereas the word bake goes with bread, cake, cookies and muffins.
When I hear the word roast, a turkey or chicken comes to my mind but in case of word bake, I imagine a pound cake; but I don't think that these explanations cover everything or most of dishes we cook in an oven.
I think what causes confusion is when we cook vegatables as a main dish and not as a side food. I mean when we cook poultry in oven, we are likely to roast it or when we bake a muffin we definitely bake it.
But I'd like to ask how about vegetable-only dishes ? E.g. in the picture below :
(zucchini + tomato )
And would you cook, roast or bake a pizza with a chicken topping?