The Query command enables you to select entities that are hidden or overlapped (for example when you need to select a hidden face/line that is adjacent to one visible line Model/face, and you do not want to rotate the model.
Snap a surface/line/curve of a model/drawing and right-click to choose the SelectQuery from the context menu. You will get a window listing of all the underneath entities (surface, lines, curves etc) of the model/drawing. You can toggle and select among the entities from the listing window.
The alternate way to use the Query command is by selecting the Automatic query selection check box from the System Options- Input category. It also displays the number of entities which are underneath the snapped entity (based on depth order). You will be able to toggle among the entities either by using the Tab or Page Up/Page Down keys.
When you start the command, the program enables you to cyclically move the selection to the next or to the previous entity.