While reading i was asked to save the html file as in .html or .htm but i don't understand

Question

HTML basis

Answer 1

Just use a name like

Example.html or Example.htm

it will tell your computer it should be open via web browser.

Answer 2

if you already saved the file however, just rename with .html at the end and it'll work as if that's how you saved it originally

Answer 3

ok so this practice has to be done with my computer. I was busy using my phone all this while...thanks Michael and William