Your drawing is probably build up out of different kinds of entities. To explain your drawing you can add a legend. With 'Quick Legend' you can pick the elements you want to add to your legend just by selecting entities. You can select any entity you want but the most important types of entities are hatches, blocks and linear entities. Before you start to select entities you need to pick a point. This will be the position of the legend. Then you can select entities and every time you select one it will be added to the legend. If you select a hatch the command will add a box with that hatch and the layer name as legend entry. When you select a block the command will add that block to the legend and will use the block name as entry. By selecting a linear entity the command will add a box with a polyline and the layer name as legend entry. Besides that the command will add a quantity. For hatches the command will add the sum area of the hatches with the same properties, for blocks the number of times it's represented in the drawing and for linear entities the sum length. Legends are added to guide the reader through a drawing. That means that any graphic difference potentially should get it's own entry in the legend. That's why the command will consider several properties. If you select an entity which is already added to the legend the command will give you a warning and will not add it to the legend. That way every legend entry is unique. If you need to work with the quantities you can decide to export the numbers to Excel while you are making the legend.