Everyone in a given location is eligible. An example is Alaska Permanent Fund where every member of the state gets an annual payment. No requirements are needed to receive payment.
The amount is approximately sufficient to meet basic needs. Often this is targeted to a specific group like lower income new mothers.
One-time transfer of cash as opposed to regular installments
the amount is intended to be a supplement, but not to ensure basic needs
Someone’s Basic Income could never be taken away, it would:
Basic Income Today: