HTML <button> explain please

Question

I completed the HTML course a few days ago and I went through some HTML codes and I saw a <button> being used, though I'm almost 100% sure I didn't see it in the HTML course. Would someone please explain the <button> for me?

Answer 1

https://developer.mozilla.org/en-US/docs/Web/HTML/Element/button
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/button

Answer 2

It is in the HTML course. I just completed it again do it is there.