Term insurance is the simplest and purest form of life insurance — you pay a premium for a set policy term, and if you pass away during that term, your chosen beneficiaries (usually your family) receive a lumpsum payout called the sum assured. If you outlive the policy term, there's typically no maturity payout at all, and the premiums you paid are not returned.
Because it offers no savings or investment component, term insurance is dramatically cheaper than plans like endowment policies or ULIPs for the same amount of cover, which is exactly why financial planners generally recommend it as the primary way to protect your family financially. A common rule of thumb is to have cover worth at least 10 to 15 times your annual income, so your family could maintain their lifestyle and meet major goals even if you weren't there to earn.