A more thorough explanation:

Definition: Functionality refers to the quality of a product or design that enables it to perform its intended purpose effectively and efficiently.

In the context of trademarks, functionality can refer to a design or feature that is so essential to a product that granting exclusive trademark rights to the first user would hinder competition. For example, if a company creates a new type of screwdriver with a unique handle design that makes it easier to grip and use, they may not be able to trademark that design if it is deemed functional and necessary for the screwdriver to work properly.

Another concept related to functionality is aesthetic functionality. This refers to a design or feature that is necessary for a product to function as intended, and therefore cannot be protected by trademark law. For example, if a company creates a new type of water bottle with a unique shape that allows it to fit in a cup holder, they may not be able to trademark that shape if it is deemed necessary for the bottle to function properly.

Overall, functionality is an important consideration in product design and trademark law, as it can impact a company's ability to protect their intellectual property and compete in the marketplace.