A Reviewable Life Insurance policy is where the price of the premiums usually starts low and then, after a few years, the policy is reviewed to determine whether the premium will change. A review will usually be carried out every five years. A review is necessary to see if the payments you are paying provide the level of cover required.
However, if you are very young and you cannot afford to pay a lot by way of premium payouts, this might be a good way to start. It means you have very little to spare when you are young but hope to earn more and afford more as you grow older.