Substrates are materials or surfaces on which organisms grow or are attached. In biology, they can refer to the base layer that supports the growth of plants, fungi, or microorganisms. For example, in gardening, soil acts as a substrate for plants, providing nutrients and stability. In the context of technology, substrates can refer to the base materials used in electronics, such as silicon wafers in semiconductors. These substrates provide the necessary support for the components of electronic devices, allowing them to function properly.