A single policy is simple. It’s where you are the only policyholder and, when you die, the money goes to your beneficiaries.
Joint life insurance is different. It’s kind of like a two-in-one life insurance policy, so it’s usually more affordable than two singles.
A joint policy will only pay out once, however, so if Partner A dies the lump sum is paid and that’s the end of the policy. Partner B will have to take out another policy if they’re to protect themselves again.