As already been said, an Oscilloscope is for more professional work. As an example you can take a look at the iPod Remote Protocol (https://tinymicros.com/wiki/Apple_iPod_Remote_Protocol) or watch Jeff Geerlings video about the device (https://www.youtube.com/watch?v=IRBT0N67YFA)

In general you probably don't ever need one, if you're not too serious into electronics - that is why I put one in the "more advanced" listing.