What is the difference between a comma and a semicolon? How do you determine when to use one or the other?
Commas have many purposes. For example, they can separate phrases from independent clauses. Another function would be separating two independent clauses, and yet another function would be separating the elements of lists, a series, or sequences.
On the other hand, semicolons connect independent clauses; they usually signify a closer connection than a period does.
Note: For examples of how commas and semicolons are used, refer to the above paragraphs. ;)