The Sega Saturn is a console made by Sega. At the time, it was considered a very complex console to program and also used quads rather than polygons. It was successful in Japan however it was a failure in the US and Europe and one of the contributions of Sega going 3rd party. Rather like the PlayStation, there were games that were in 3D however there are plenty of 2D games as well including various arcade ports some that even used RAM cartridges.
The Saturn uses CD-based technology, meaning that all of the data found within a game can be read using a standard ISO viewer, or by inserting the disk into your computer and browsing it. Some games come with bonus images that can be viewed on a computer, these are found in the OMAKE or the Extra folder and they are in BMP.
Sonic Jam uses TIF files for the manuals that appear in the game, these can be viewed via Irfanview or any software that accepts .TIF.
Mednafen is currently the most accurate Sega Saturn emulator and runs many games without problems. It is still work in progress despite this and may even get more accurate in the future. There are two downsides though, one is that is requires a really powerful computer that is 64 bit to run all games at full speed and two there is some input lag that has been reported.
It is also available in BizHawk however it is based off an older version and does not have all the fixes that the latest Mednafen has.
The advantage over Mednafen is that you can rip sprites on it since there is a sprite viewer. Sadly though the emulation isn't as accurate as Mednafen so as a result, compatibility is much lower with some games not working at all or heavily glitchy. Another issue is that because of how people rip ISO/BIN+CUEs, ones that work on Mednafen do not work on this and vice versa.
Yaba Sanshiro is a forked version of Yabause that includes improvements.
There is also SSF that for years was considered the most accurate Sega Saturn emulator and for some games more accurate than Mednafen however the major disadvantage is that it only accepts discs from a disc drive or mount a disc using a virtual disc drive but many do not work on SSF and many are virus or malware ridden. Due to this, it is hard to recommend for this reason alone.