A startup is defined as a temporary organization designed to search for a scalable and repeatable business model under conditions of uncertainty. The real purpose of a startup is to deliver a new product or service in an uncertain environment. Effective startup practices include having cross-functional teams that draw, prototype, and test ideas, acting like an established company from the beginning, organizing tasks and communication properly, and finding a clear goal or "north star" to guide the organization. Metrics and legal shareholder agreements are also important elements of successful startups.