What is a marquee? How to use it?

Answer 1

The HTML <marquee> element is used to insert a scrolling area of text.

See this jsfiddle DEMO :
https://jsfiddle.net/api/mdn/

Also refer to this MDN Page:
https://developer.mozilla.org/ar/docs/Web/HTML/Element/marquee

Answer 2

marquee tag used movement of text or image ex <marquee>hi everyone/marquee> its default take left to right movement if we want chance the direction using direction attribute make it possible left,right up,down

Answer 3

marquee tah used to move some specific text/image
like from left to right, or right to left, top to bottom. it have 3 different styles too, scroll, alternate and slide , for more attributes check w3school or tutorialspoint