A button is an interactive element that enables users to get the expected interactive feedback from the system following a particular command. Basically, a button is a control that allows a user to communicate directly with the digital product and send the necessary commands to achieve a particular goal. For example, it may be the task to send an email, buy a product, download some data or a piece of content, turn on the player, and do tons of other possible actions. One of the reasons why buttons are so popular and user-friendly is that they efficiently imitate interaction with objects in the physical world.