Besides offering a fully redesigned user interface that introduced the iconic Start menu, Windows 95 was a lot user friendlier than previous versions of Windows, it had much better file management as well as enhanced multi-tasking support.
A lot of revolutionary features at the time are quite mundane today, including the introduction of GUI-based cut and paste support, support for file names longer than 11 characters, plug-and-play support, the recycling bin, right button menus, etc. But while it was a big step up, Windows 95 was far from perfect of course. In fact, as a power user you'd be lucky if the OS crashed only once a week.
Here's a copy of the promotional video for several early Windows 95 applications that was sent to retailers for the Windows 95 launch:
And here we have some footage from the Windows 95 launch event:
For a look at what Windows 3.11 felt like, here's a video of a first-time user. It's kinda long-winded but it gives you an idea of how Windows operated before the launch of Windows 95.