Freehold ownership is when you own your property outright.
See here to find out what the difference between freehold and leasehold is.
If you own a house, whether or not you are a member/shareholder in a RMC, it is usual that you should arrange your own buildings and (optionally) contents insurance. In this case you will find that you have not been charged for buildings insurance by the RMC.
Sometimes a property may be part of a larger development where the owners share maintenance responsibilities for common areas, footpaths, even roadways.
In cases such as this it is likely that the situation came about on account of requirements placed on the developer by the local authority as regards ongoing maintenance of common areas that might otherwise been adopted and maintained by the local authority.
A Rent Charge is a charge placed on a freehold property. It may also be known as a Chief Rent. The amount of the Rent Charge payable will be set out in the conveyance (the document that records your ownership). That same document may also set out certain conditions placed upon you, known as the Covenants.