Dyke and sill are both terms used in describing the environment. They are used to describe invasions that happen when a volcanic rock enters into and implants another layer of rock. One difference between them is how they are grouped. Dykes can be grouped into rhyolitic, diabase, or granitic. Sills are normally just grouped into medium size granite rocks. Another difference between them is where they are made. Dykes are normally parallel to bedding planes. This is compared to sills, which are much harder to see, as they are parallel to rocks and planes. They are also parallel to the original formation of the rock.
Dyke and sill are environmental terms used to designate an invasion, typically a mass of igneous or volcanic rocks that have effectively entered, penetrated, and implanted into layers of additional rock or landform. Dykes and sills are often connected with volcanoes, though they are not limited to those landforms.
Dykes are vertical. Their creation is reliant on the consistency of pressure that comes. The usual grouping of dykes can be diabase, basaltic, to granitic, or rhyolitic. Dykes are made to be in between and parallel to their surroundings bedding plates. On the other hand, sills are created the same way.
Sills are generally comprised of medium-grained rock and often encompass certain rare types of deposits in their formation. A sill as a form of rock is concordant because it is parallel to the original rock or landform. Sills are harder to identify since they exist parallel to planes and rocks.