One of the frustrations of being a mere photographer of insects is that it can be a bit difficult to tell what you've got a picture of. The first shot below looks like a wasp or hornet if one takes a quick glance. However, it's a hover fly mimic. Identifying this insect is a bit easier as flies eyes are up front as opposed to being on the sides of the head. Also their wings sit out away from the body. Wasps wings lay a little closer to the body and are thinner. Bees wings tend to fold over the body.
The next photo is a bit tougher. Mainly because I can't tell if it's a small bee or a small wasp. I'm leaning towards bee. However, it's difficult to tell from wing shape, head size or what the eyes look like.
I supppose I could get an etomology text book and start an insect collection. Maybe even take some classes. I haven't yet because, for the most part, I'm OK with a general idea of what I have a photographed. If I can get it down to the species level, that's great. If not, I know it's a fly. Also, I don't have the heart to gas insects then pin them to a board.