A Graphical user interface (GUI) is important because it allows higher productivity, while facilitating a lower cognitive load, says About.com. Graphical user interfaces allow users to interact with computers using a mouse and other input tools. They give developers more freedom with how they display information, images and other elements.
According to ARS Technica, Douglas Englebart was the first to spur interest in GUIs in the 1960s. His work explained how GUIs can increase productivity in certain scenarios. Certain types of software are dependent on GUIs. Adobe Photoshop and other graphics programs require a mouse to function properly. Other types of software benefit from the simultaneous use of multiple windows. While servers are often configured with text files that can be modified from command line interfaces, GUIs have become popular tools for monitoring and tweaking servers.