What does<input type="radio">do?

Question

Defines a circular selection button in a form.

Answer 1

When there are multiple choices but user can choose ONLY ONE option, use radio button. If user should be able to choose multiple answers, then use checkbox instead.

Answer 2

Thats a Radio button

Answer 3

Defines one choice at a time menu,
eg. you have seen to select gender,
you can choose either one. That's radio.

Answer 4

yeah that's it then you can use that as form of selection.