As a new governor, I can see the benefit of having a mix of different interests, but I am not very clear about how far we are expected to represent those points of view.
First, all governors should play an equal part in the work of the governing body. Second, they make decisions by agreement and if necessary by majority vote; no governor has the power to act alone, and all must honour group decisions. Third, every governor is free to contribute and vote according to his or her view, after discussion, of what is in the best interests of the school. Nobody is obliged to take a "party line" or can be disciplined for not doing so.
Having said that, we are all representatives. That doesn't mean we cannot act as conscience dictates, but that we have a listening and communicating role for the group we represent even if at times we don't agree with the group. This ensures the wide mix you refer to, and it enriches the governing body and ensures that all partners in the school have an input.
LEA governors do not have to take a political point of view, although they sometimes do. They represent the education authority as a whole and should know its policies and be prepared to explain them, even if not supporting them. An LEA governor would also take a view sometimes about the effect of school decisions on the local education service as a whole and, if necessary, may remind colleagues of these. But first loyalty must be to the school.
Foundation governors (mainly in church schools) represent the voluntary body that set up the school. They do have certain formal responsibilities (depending on what the trust deed or similar document says) for ensuring that the purposes for which the school was set up are not forgotten. This means that often they have to have regard to its moral and spiritual purpose and sometimes the interests of a parent church, as well as being responsible for the quality of education provided.
Parent governors are elected to bring parents' views to the school. They do not have to do what parents ask, but as representatives they do have a duty to listen, to bring parents' concerns to the governing body and to report back as appropriate. "Appropriate" means avoiding matters classified as confidential, being scrupulously accurate and reporting discreetly, confining reports to decisions and reasons, without revealing the part any governor played or being disloyal to any colleague.
Teacher governors bring the teaching staff's concerns to the rest of the governors, just as parent governors do those of parents. They too are free to vote as they think the best interests of the school require, but they should always report any staff views to colleagues as well. They should report back in the same responsible way as recommended for parents.
Co-opted governors are chosen from the wider community. They too are free to act as conscience dictates, having listened to other views. But good co-opted governors will also be watchful that the school is a good neighbour, considerate of the impact it has on the community and sharing its facilities as far as possible with the community. It is valuable to have this wider perspective - a reminder that schools are not ends in themselves, and to have a listening ear outside the school.
That is the mix, and it normally makes for a rich and well-informed discussion and - it is to be hoped - decisions which do not forget the viewpoint of any of the groups that have an interest in the affairs of the school.