windows 9X added 32bit power (excluding Win32S stuff) Windows 3.1 and lesser were 16 bit just like DOS but provided multitasking and a GUI.
Windows 9X is an OS, you can run stuff in it that DOS can't run. Same goes for Win3.1, IIRC though to a lesser extent (for one thing most proggies were DOS anyhow)
MMMMM Swedish Fish, god's candy, well God's and the wax companie's.