Substitutes

A substitute, or substitutable good, in economics and consumer theory refers to a product or service that consumers see as essentially the same or similar enough to another product. Put simply, a substitute is a good that can be used in place of another.
Substitutes play an important part in the marketplace and are considered a benefit for consumers. They provide more choices for consumers, who are then better able to satisfy their needs. Bills of materials often include alternate parts that can replace the standard part if it's destroyed [Investopedia].

Something or someone that takes the place of another is said to be a substitute. You may be sent into a game as a substitute for an injured player, or you might substitute chocolate chips for blueberries in a pancake recipe.
A substitute can be used as an adjective to describe something or someone that takes the place of another. Teenagers are notoriously hard on substitute teachers, sometimes giving them fake names or wrong information about classroom work. A substitute can also be used as a verb [Vocabulary].

Sources:

What is a substitute? Investopedia. Retrieved from: https://www.investopedia.com/terms/s/substitute.asp

Substitute. Vocabulary. Retrieved from: https://www.vocabulary.com/dictionary/substitute