People Use Me, Yet Can't See Me. People Can Trap Me But I Can Easily Get Free

Riddle: People use me, yet can't see me. People can trap me but I can easily get free. If people don't use me, they die. What am I?

Answer: Air.

Source: https://www.riddles.com/6301

People use me, yet can't see me. People can trap me but I can easily get free. If people don't use me, they die. What am I? — People use me, yet can't see me. People can trap me but I can easily get free by Anonymus v1.

Riddle: People use me, yet can't see me. People can trap me but I can easily get free. If people don't use me, they die. What am I? Answer: Air. — by Anonymus v2.