dry soot on spark plugs

i changed my spark plugs today. My old plugs had some dry soot deposits on the them. what does this mean? i seem to recall that one thing it means is that i am running rich. What does running rich mean though?

thanks

does it look kinda of a light gray?

no a deep black

sounds like ur running rich
or could be oil :uhoh:
could be gas (meaning ur running on 3 cylinders cuz it isnt igniting)

the main thing is how is the car running now?

I would change your pluggs wires if your other plugs are fine your car was probably missing right

they all had the black soot on them. it wasn’t that much or anything maybe it is noramll amount. This is the first time i have changed spark plugs on a car