Depends if they have any assets, they have to pay themselves until those assets are reduced to £23500 when they will receive some funding from social services. If they require Nursing Care within a Nursing Home they should then receive a contribution towards the nursing element from the NHS. If they do not have anything at all then fully funded by Social Services/NHS.
If only asset is property but somebody else lives there then different rules come in depending on who the other occupant is and they may then again qualify for Social Services funding.
If you look at Age UK site or NHFA site they will be really informative and you will be able to relate them to your particular circumstances.