Windows 98
Windows 98 was designed to be an upgrade to Windows 95.
While Windows 95 was substantially different from its predecessor Windows 3.1, Windows 98 and Windows 95 look and feel almost the same.
Windows 98 for lack of a better term is basically a revision to Windows 95 – not entirely different but like Windows 95 with some niceties, some bug fixes, better hardware support and able to do a much better job integrating your computer with the internet (world wide web).
If I may be allowed to interject a bit of humor, Windows 98 is simply Windows 95 after a couple of years on the job. It is a little bit faster, a little bit more reliable and a tad bit better at navigating itself (and you) out of tricky (computer) situations.