operating systems

Windows 95 was the first version of Windows that was allegedly DOS-free, tho' it wasn't completely.

Windows 98 was the next version of Windows that included many bug fixes from 95 (but included many of its own). Its claim to fame was that it wasMSs first attempt to integrate the browser with the OS (aimed to kill Netscape).

There was no 97, but you missed in the list WindowsME -- an "upgrade" of 98.

These OSs are generally considered to be home user OSs.

Windows NT was designed byDavid Cutler who was a primary designer of VMS, from Digital Equipment Corp. NT stood for "New Technology" (among other tings) and 2000 was its successor. Both of these are generally considered to be more stable than the 9x varieties and are what most businesses are (or should) be using if they want to be using Windows.

Windows XP (also missing from your list) is the latest incarnation of the OS.

To detail all of the differences, would take a book.

95 was the first full multi-tasking GUI from Microsoft.

98 added support for large drives (FAT32) and proper implementation of USB devices

NT is a business version of 95, it is more robust and stable. But lacks many of the features required to play graphics based games.

2000 is the second generation business OS, and the first OS to move away from the DOS core. Again, like NT it is designed to be robust and stable, but doesn't play games well.

XP fully departs from DOS, and combines the robustness of NT/2000 with the gaming abilities of 98.

This is a course thumbnail, but gives you the general idea.