Your landlord is the building owner and so is required to cover the property for buildings insurance if anything should happen the house.
Any contents within the house, owned by you, are your responsibility to cover and replace them if needed. Therefore you can get contents insurance to cover the cost of replacing your property if required.
There are also differences in the policies as contents cover has different requirements for renters and owners, one being 'tenants liability insurance'. This covers damage to the landlord's fixtures and fittings and can be included if you select that you are renting, make sure all your details are correct to be fully covered!