So what does this even mean?

One of the most difficult writing features to develop (and to teach!) is paragraph develoment.

The idea is that once you have written your main topic sentence, you then need to flesh that topic out in terms of detail and logical transitions.

Transitions (showing relationships):

Above all, After all, Again, All in all, Also, Alternatively, Although, Aside from, At first, Because, Briefly, By and large, By the same token, By the way, Comparatively, Especially, Excluding, Finally, First of all, For example, For instance, Generally, Hence, However, In addition, In any case, In any event, In brief, In conclusion, In essence, In other words, In particular, In short, In some cases . . . , In the final analysis, In the long run, In the meantime, Including, Likewise, Meanwhile, Moreover, Namely, Nevertheless, On the other hand, One way, Ordinarily, Other than, Particularly, Regardless, Similarly, Simultaneously, Subsequently, That is to say, Therefore, To summarize, Whereas, While