Do you need car insurance to drive cars belonging to others?

Broadly, the answer is "yes", if the point is to be covered in the event of a collision.

The coverage can be provided by means of the driver being named on the application for insurance, and designated as an authorized user of the vehicle. A premium will be calculated based upon the risk factors attending the use of the car by all authorized driver, the type of vehicle, and other factors allowed by law to be considered by the insurer.

The driver can also obtain "non-owner's coverage" which will generally provide coverage regardless of the vehicle being driven. This is often obtained by someone who does not own a car.

Finally, some commercial policies cover a range of people on a range of vehicles, but the vehicles and the authorized drivers have to be identified to and approved by the insurer.