Substrate may refer to:

Physical layers

Substrate (biology) In biology, a substrate is the surface on which an organism (such as a plant, fungus, or animal) lives. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock (its substrate) can be itse ...

, the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (locomotion), the surface over which an organism locomotes ** Substrate (marine biology), the earthy material that exists in the bottom of a marine habitat, like dirt, rocks, sand, or gravel *

Substrate (building) The word substrate comes from the Latin '' sub - stratum '' meaning 'the level below' and refers to any material existing or extracted from beneath the topsoil, including sand, chalk and clay. The term is also used for materials used in building f ...

, natural stone, masonry surface, ceramic and porcelain tiles * Substrate (chemistry), the reactant which is consumed during a catalytic or enzymatic reaction ** Substrate (biochemistry), a molecule that is acted upon by an enzyme * Substrate (materials science), the material on which a process is conducted * Substrate (printing), the base material that images will be printed onto *

Substrate (vivarium) The substrate of a vivarium is the material used on the floor of the enclosure. It can affect humidity levels, filtration as well as the well-being of the inhabitants. The appropriate substrate depends on the type of animal in the enclosure. Functi ...

, the material used in the bottom of a vivarium or terrarium **

Substrate (aquarium) The substrate of an aquarium refers to the material used on the tank bottom. It can affect water chemistry, filtration, and the well-being of the aquarium's inhabitants, and is also an important part of the aquarium's aesthetic appeal. The appropr ...

, the material used in the bottom of an aquarium *

Printed circuit board A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a L ...

(PCB), or more specifically, the electrically insulating portion of a PCB structure, such as fiberglass bound together