Substrate

Substrate may mean:
 * Substrate (biochemistry), a molecule that is acted upon by an enzyme
 * Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached
 * Substrate (chemistry), the catalytic material upon which chemical species react

Substrate may also refer to:
 * Wafer (electronics), material upon which semiconductor devices are fabricated
 * Printed circuit board (electronics), or the electrically insulating portion of a PCB structure