Do you really need a special headset that is also designed for gaming?
You don't need anything that is designed for "gaming". There are only a few products like this. And then I can only think of 240 Hz screens.
What should be different about a gaming microphone? Nothing. Except that the headset is an expensive plastic marketing bomber that costs 10 euro more because it says "Gaming" or some pseudo-cool English words that children find cool because it sounds crass in English.
No, theoretically you could also gamble with normal cellphone headphones, it depends on what kind of quali you want and for some games or for most of them you need a good headset to hear all the details
What should be different about a headset, i.e. Headphones with a microphone, so that it changes from a normal to a gaming headset?
No, you don't have to spend an extra 60 euro to make the thing yellow, look like a robot skull, and say "Gaming" on the box. Find a headset that is priced ok for you, that you can ideally try on, that is good.
You only need a microphone installed
Then it's an earphone and not a headset.
Gamer2005 You can also just use normal headphones, for example those from your cell phone (I only gamble with cell phone headphones)