Non-functional requirement

Non-functional requirements are rules that explain how something should be made or behave. For example, if we are building a table, a non-functional requirement could be that it should be sturdy and not break easily when someone sits on it. Another non-functional requirement could be that it should look good and match the style of the room.

These requirements are called "non-functional" because they are not related to what the table does (like holding things). Instead, they are focused on how the table is made (its quality) or how it should look (its appearance).

Non-functional requirements are very important because they ensure that the final product is not only functional (it can do what it's supposed to do), but also of high quality and visually appealing.