Donuts are sweet cakes that resemble bread. The shape is round and hollow in the middle. There are also donuts that are not hollow and the center is filled with fruit jam or other sweet foods Donuts are made from flour, butter, and sugar. The mixture is mix until blended and formed into a round and the center is punched. Donuts can be fried and baked, but are generally fried until golden brown. It made donuts has shiny texture on the outside and soft on the inside. The ingredients for making bagels are not much different from donuts. But in bagel dough, yeast is added and becomes an important ingredient. After the mixture is evenly mixed, the bagel is shaped by twisting the dough to resemble a rope and forming it into a round

You question is not stupid. Bagel is enriched round shaped bread. Doughnut is very sweet, coved with chocolate or other sweet icing.

Bagel - salty Donut - sweet

People answered your question well but I wanted to make another suggestion as well. Of course asking on here is great too, but for these kinds of things it works well to go to a search engine and type each word (separate searches) and then go to images. I don't mean that at all as that you shouldn't ask here as well, but it's a nice trick for learning vocabulary and helps a lot when learning languages.

A bagel is more like bread and usually eaten in a similar way, sliced with a filling in the middle. A donuts is deep fried dough, usually covered with a sweet topping. Both have a hole in the middle though ;)