The famous Penny Bun (Cep, Porcini, Steinpilz) is generally considered to be the best of all the edible species and is collected in vast quantities in many parts of the world. Several other species are edible, some only when cooked. The Bay Bolete is prossibly the best of these, provided it is young and firm. A few species are poisonous, notably the rare Satan's Bolete.
The group is characterised by the tubes and pores visible beneath the cap, though at least one species has gills!
The taxonomic order, Boletales, is notoriously varied. Although members of the family, Boletaceae, look at least a little bit like the Cep, other families are wildly different morphologically. For example, the Earth Ball is in the Boletales, but looks like a yellow, scurfy ball on the forest floor.
This is a one trick wonder mushroom as it is only found parastising a single species of Earthball. Fairly common and always a delight to see.