A C. of E. (Church of England) school is a school that is not owned by the Local Education Authority (LEA), but which is operated under funding supplied by the LEA. The school grounds and building were originally provided by the Church of England, who support the maintenance of the building fabric and grounds. The local parish church also takes a keen interest in the running of the school and supports the elements of the school's religious curriculum and moral teachings. This is as opposed to a 'County School' that is wholly owned and provided by the County Council and LEA.
St. Mary's is also a "Voluntary Aided" school, the principle effect of which is that the local parish council appoints more 'Foundation' Governors than all the other types of governors added together. The other type of Church of England school is a V.C. school (Voluntary Controlled) in which the LEA appoints more Governors than the local parish council. The decision of whether a school is a VA or VC school was made by the Governors at the time that these categories were defined, some years ago.
V.A. schools also have more complicated rules for the repair and improvement of the building than County Schools. Some of the funding for repairs comes from the LEA, whilst others come from the local Church of England Diocese; Salisbury in our case.