I have a 2012 iMac with 2 thunderbolt/usb4 ports. What can they be used for

The only reason I say thunderbolt/Usb4 ports is that is what is listed under the about under the spec for thunderbolt. I am totally confused. It also say I have 4 Usb2 ports not usb3. Anyway what cable to I need to use these thunderbolt ports as all my usb are in use. Any ideas would help. Thinking of getting external hard drive but not sure I know which one could plug into my Mac and it’s thunderbolt ports I have.

To be clear I mean under the Apple top left and about this Mac and then it has a place to see more. There it shows slot of stuff that you can click on that tells you more info on whatever I clicked on. When I see thunderbolt and clicked on that is says thunderbolt/usb4. I will take a picture of that tomorrow. It does not say thunderbolt4. From what I understand now I have thunderbolt 2 is that correct? So when I buy a device I need it to be compatible with that and then I will need a cable that goes into my thunderbolt 2 out to new device that can use this thunderbolt connection properly. Maybe they sell one that comes with the proper thunderbolt cable which would be what exactly. Thunderbolt 2 or just thunderbolt.