What's the difference between electromagnetic waves and electromagnetic spectrum?

The difference between the two is, well for one

Spectrum: The entire range that the "waves" could be such, as visible light, x-ray's and so on.

Waves: These are different because they aren't telling you or showing the entire spectrum just which they length that they are.

It may confuse you but it makes sense to me (Sorry)

This is what i found on google “lithium and sulfide can react together to form litium sulfide(li2s). when lithium sulfide hydrolyses(breaks down) in air, it releases hydrogen sulfide which is characteristized by a rotten egg odor.” i hope this you for what your looking for