3 PINs = addressable RGB (ARGB). That means the LEDs can be controlled separately to make various effects.
4 PINS = RGB. That means you can still change colours, but all the LEDs will be the same colour.
You can buy an ARGB controller, which is basically a box you plug all your ARGB stuff into. They're not too expensive. I've never used one myself, but it looks pretty simple. You might want to check whatever you buy has long enough cables so you can connect everything neatly and put the cables out of the way. You can buy ARGB extension cables.
Just make sure you're getting the right thing and don't mix up RGB and ARGB.