Dissolves belong to another class of transitions also known as "digital effects" or just "effects." The dissolve is the simplest, but some of the dozens of digital effects available in Premiere or other desktop video software can be very elaborate indeed, resembling or duplicating the flying logos that have become standard in broadcast television. Experimenting with these transitions can be fun, but as often as not, the results are out of step with the message being communicated or even look downright silly.
Unless of course you're producing for MTV!
Another thing to keep in mind is that digital effects, including dissolves, take longer than plain cuts to compile when previewing your movies, thus slowing down your progress. Plus, including a lot of digital effects will cause the filesize of your final movie to increase rapidly: not good if you want to distribute the movie on the web, at least while bandwidth remains the chief bottleneck.