I would guess that most Greek students think of the aorist tense as a general, nondescript tense. In one sense, this might be somewhat accurate. The aorist is certainly the default tense. If you want to describe an action occurring normally in the past and you don't want to say anything else about it, the Greek writer defaults to the aorist. When the writer wants to make a specific point, the other tenses come into play.
However, the aorist can be more nuanced than that. While its basic meaning is to look at an event as a whole from the outside, it can also carry specific meanings that are indicated by context.