Parallel....series....

What comes to mind without looking it up:

Parallel - Running in the same direction.

In series - One right after another.
This is how an electrician friend explained it to me decades ago...just one of those things that goes away...Thanks...
What are you doing, Doug?

Series think "in line" like flashlight batteries in a flashlight, voltage adds the total of the individual. Neg to pos.................neg to pos...........neg to pos........

Parallel, "side by side" you could parallel 2, 20, or 200 million D cells and the output voltage will still be 1.5V nominal.........neg to neg...........pos to pos

Jumpering a vehicle battery is parallel.......more amps, same voltage
Nothing in particular Del. Was just reading a thread on here where you are working with someone who popped a link. Read your posts numerous times trying to remember but...well...the hamster just couldn't spin the wheel fast enough.