What is a monocular?

I’m very interested in what a monocular is, I’m wondering whether I should buy it or not, what is its function?

In general, a monocular is a mini telescope through which you can look at an object closely, only more conveniently. Check out these models https://www.atneu.com/thermal-monoculars. Maybe you’ll decide to buy one for yourself, since I’m already buying a second one, I really liked the store, it’s honest and has very high-quality thermal imaging monoculars.