The comma has several uses in English grammar, all related to marking-off separate elements within a sentence.
Rule #1Use a comma before the conjunction (FANBOYS or for, and, nor, but, or, yet,so) that joins the two independent clauses in a compound sentence
Examples: I like jogging outside, and I also enjoyreading.
Rule #2Use a comma after introductory phrases ordependent (subordinate) clauses.