Dimensions in Drawings

Dimensions in a SOLIDWORKS drawing are associated with the model, and changes in the model are reflected in the drawing.

Model Dimensions Typically, you create dimensions as you create each part feature, then insert those dimensions into the various drawing views. Changing a dimension in the model updates the drawing, and changing an inserted dimension in a drawing changes the model.
Mark for Drawings You can specify that dimensions marked for drawings be inserted automatically into new drawing views. Go to Tools > Options and in the Document Properties tab, click Detailing. Select Dimensions marked for drawing under Auto insert on view creation.
Reference Dimensions You can also add dimensions in the drawing document, but these are reference dimensions, and are driven; you cannot edit the value of reference dimensions to change the model. However, the values of reference dimensions change when the model dimensions change.
Standard Dimensions You can create standard dimensions in drawings, such as dimensions created in a sketch. This includes Smart, Horizontal, and Vertical dimensions.
Rapid Dimension Use rapid dimensioning to place evenly spaced dimensions.