It protects both.
The production company is protected from claims arising from their legal liability and damage to equipment, sets and props.
If you purchase media production or commercial producers’ indemnity, the policy also provides essential protection for your client, as it covers their investment/budget and reshoot costs so if things go wrong, your client won’t end up paying twice.
Remember though that your cover for reshoot costs will depend on whether you have media production or commercial producers’ indemnity.