What is the difference between Series and Parallel?
Simple understanding of Series and Parallel Connection
Here is an image that depicts the difference between the two connections. Notice that on a parallel connection the voltage stays the same but the current doubles, and on a series connection the voltage doubles and the current stays the same.
The recommended way is usually to have a combiner box at the location of the panels, that way there is only a single set of wires that come from the panels into the SCC.