User interfaces are designed to be highly useable and efficient. Users should be able to use interfaces to achieve their goals in a simple and timely manor.When an interface is engineered for its users it becomes second nature to use. Effectively becoming unnoticeable and out of sight. In an efficient design the interface becomes non-existent and removes all barriers between the users goals and what the interface achieves.The sole task of a UI design is to become invisible. It focuses purely on the interface whereas UX design is broader and extends to all brand touch points, social media accounts and any other interaction that user has with a brand.
