It's easier to describe an explicit solution, in this case and then tell you what an implicit solution is not, and after that provide you an illustration to demonstrate you the difference. Thus, that is what I'll do.

An explicit solution is any solution which is specified in the form y = y (t).  Conversely, the only place that y in fact shows up is once on the left side and only increased to the first power.  An implicit solution is any solution which isn't in explicit form.  Notice that this is possible to have both general implicit/explicit solutions and actual implicit/explicit solutions.