Different products have different objectives. Sometimes a product has one single objective or several different objectives that form its overall experience. As a rule, all the elements of the design of the product (functional, experiential, visual) must work together to help the user achieve her desired objective.
Single (simple) objective:
When a product has a single objective, all the elements of the product converge to achieve one specific goal. For example, in Citymapper, a mobile application that gives you directions for getting around a city, all the elements guide the user to a screen showing a selected journey. When you use Google Search, your single objective as a user is to obtain a useful piece of information.
Multiple (complex) objectives:
Some products have several objectives. The configuration of these products is far more complex as multiple elements have to coexist and interact without creating confusion for the user. Let’s take a look at Gmail. Although the main purpose of the service is to allow its users to “easily send and receive emails, the application has a broader scope and multiple objectives.
Only sending and receiving emails is not enough, because a constant inflow of emails creates other needs and therefore new objectives. For instance, a deluge of emails requires features allowing users to filter and organize their emails. Furthermore, the fact that email has become a universal tool for organizing your personal and professional lives creates new goals, such as organizing contacts or add appointments to a calendar.