First, you don't sound like a fool for asking. There are a lot of women on here that could give you a more technical, better defined answer but spinning has to do with your riding cadence, or the rate of the revolution of your pedal stroke. If you are a "spinner", you pedal at a faster rate of speed using a smaller gear. If you are a "masher", you pedal at a slower rate of speed using a larger gear. You can travel at the same speed using either a fast cadence and smaller gear or a slow cadence with a larger gear.
Whether you spin or not depends on your riding style, strength and personal preference. Spinning uses different muscles and won't tire your legs as quickly while mashing lets you push a bigger gear and generates more accelaration. For example, I will spin up a long hill but will mash up a short, steep climb. Mashing can hurt my knees though so I am careful when I do it.
Hope this makes sense and doesn't confuse you
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"We don't stop playing because we grow old; we grow old because we stop playing." George Bernard Shaw
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