A substance or layer that underlies something, or on which some process occurs, in particular. • the surface or material on or from which an organism lives, grows, or obtains it's nourishment. • the substance on which an enzyme acts.
A substrate is a substance that is placed under something. Substrates are substances that are placed under many things, such as a built bed frame, but there are many other things/examples in which they are placed in.
