Raman Spectra of Toluene
Chemists have tables and tables and tables that correlate functional groups to numbers.

For example:
http://www2.ups.edu/faculty/hanson/Spectroscopy/IR/IRfrequencies.html

If we see a number on the graph, a certain type of functional group may be present.  The sharp one at 3056 tells me aromatic hydrogen.  The 2919 is the benzylic hyrodgens.  Since I'm a synthesis guy, knowing the exact types of vibrations occurring there was never important to me.

Be warned, chasing every peak is normally quite frustrating.  Vastly more important is normally the overall look for comparison with a known compound, which is sort of a molecular finger print.