The difference is between a cup and a cap. The former being flat or concave so a toad can sit on it, these are generally inedible were as caps are more likely to be the eaters.
I learned by going out with pickers. Unless it specificly states as such Im not bothered by cup or umbrella distinctions. 2 general rules are red=bad and if in doubt dont eat it. I tend to go for boletus, parasols, chantrille and Puff balls as im quite confident in what I am dealing with...
Every tasty one has a horrid lookasimilar.
The third one looks like Boletus Satanus as the stem looks reddish, you need to cut said stem to see if it has yellow fluid then if so its a nasty.
First rule of Mushroooming, go with someone who knows what they are doing. Guess work and NSC...