Requirements are the specific needs or conditions that must be met for a project, product, or system to be successful. They help guide the development process by outlining what features, functions, or qualities are necessary. For example, in software development, user requirements might include the need for a user-friendly interface or fast loading times. Understanding requirements is crucial because they ensure that everyone involved, from developers to stakeholders, is on the same page. Clear requirements help prevent misunderstandings and ensure that the final outcome meets the expectations of the end users. This alignment is key to delivering a successful project.