A QHeaderView is a class from the Qt Toolkit which provides a header row or header column for item views.
A QHeaderView displays the headers used in item views such as the QTableView and QTreeView classes. It uses Qt's model/view architecture for consistency with the other item view classes.
The header gets the data for each section from the underlying model. Each header has an orientation and a number of sections. A section refers to a part of the header - either a row or a column, depending on the orientation. The sections can be moved and resized, and can also be hidden and shown.
Each section of a header is described by a specified section ID, and can be located at a particular visual index in the header. A section can have a sort indicator, which indicates whether the items in the associated item view will be sorted in the order given by the section.
For horizontal headers, the section is equivalent to a column in the model, and for vertical headers, the section is equivalent to a row in the model.
The official Qt documentation can be found here for Qt 4.8 and here for Qt 5.
