How does a laccolith differ from a sill?

A laccolith and a sill are both types of igneous intrusions, but they differ in their shape and how they form.

A laccolith is a mushroom-shaped intrusion that pushes the overlying rock layers upward, creating a domed structure. The floor of a laccolith is typically horizontal, and its diameter is usually less than 10 times its thickness.1

In contrast, a sill is a sheetlike intrusion that forms parallel to the bedding of the surrounding rock layers. Sills are typically much thinner than laccoliths and can extend for much greater distances. While laccoliths cause the overlying strata to bulge, sills intrude between existing rock layers without significantly deforming them.123