Subwoofer Speakers Is There Good Subwoofer/Speakers For A 1987 Ford F-250 And Do Speakers Have Subwoofers In Them?

Is there good Subwoofer/Speakers for a 1987 Ford F-250 and do speakers have subwoofers in them? - subwoofer speakers

I just got a 1987 Ford F-250 and I wondered why he only speakers? It comes with subwoofers in them? You can also play music with a subwoofer, or if you need both?

Thank you!