Term life is the cheapest coverage available, but term insurance is temporary, and only offers life insurance lasting for a period of up to 30 years.
However, whole life insurance which costs more provides guaranteed lifetime protection for as long as you live - as long as you pay your premiums on time.
Term life is cheaper because it is temporary, many people outlive the duration of their policy, and term life does not build up any cash value inside the policy - it is pure protection, not an investment.
Here's how to learn more about whole life insurance versus term life insurance.