I used to go to Oshkosh every year .... can't go this year because of scheduling problems.
The "AirVenture" has ~11,000 airplanes, hundereds of thousands of people over the week-long event.
The field is divided into
"WarBirds" - basically any military aircraft, ever made. Usually dozens of Mustangs, Corsairs, T-2x ... props, jets .... pretty much anything ever used by military (from many countries).
"Homebuilts" - all the various do-it-yourself airplanes .... dozens and dozens of EZ, Vari-EZ, Long-Ez, RV4s ... rows and rows of homebuilts.
"Classics" - all the old stuff ... rows of "V -tail" Bonanzas, Piper Cubs, Comanches ... again, you name it, it's probably there.
"Ultra-lites & Helocoptes" at the South end of the field ... probably the smallest group, but they get their own grass strip and probably have the most aircraft flying ost often.
Plus, all the manufacturers usually have their product line available for inspection; Beech, Cessna, Piper, Commander, Maule, Katana, Grob, Pilatus ....
Plus daily airshows, the collections of current military aircraft on display, all the cool stuff in the shopping hangers, plus the "fly-market", plus seminars and presentations (usually includes a BlackBird pilot or two, Rutan, some of the more popular authors ...), the NASA exhibits & science shows ...
Also, thousands of people fly their own aircraft in for the show, so there's rows & rows of nearly everything in the general aviation community on the ground ... many camp under their wings.
It's a good time, and virtually impossible to see it all in one day. There's plenty of good food, plenty of available water, restroom facilties ... it's a well-run show. Being that it's held at the OshKosh airport, there's not much shade or air-conditioning, bring lots of sun screen and dress for heat.
To see what's happening, check out
www.eaa.org
FWIW
Scott