A period (.) provides the strongest break between ideas.
A semicolon (;) is next, and a comma (,) provides the weakest separation.
Coordinators provide connection between equal ideas.
(and, but, or, nor, so, for, yet)
Subordinators provide connection between unequal ideas.
(because, although, when, while, if, as, since, whenever, wherever)
He didn’t go to work because he was sick.
Although John was unhappy, he still smiled.
Conjunctive Adverbs provide connection between large groups of ideas/sentences. (usually paragraphs)
(therefore, otherwise, thus, in conclusion, furthermore, on the other hand)