User interface, or UI, describes the way in which a human interacts with a machine. Though technically something as simple as a light switch could be considered an instrument of UI, most modern references relate to computers and other electronic devices.

UI makes the exchange between users and machines possible. Without it, this vital form of communication ceases to exist.

There are four prevalent types of user interface and each has a range of advantages and disadvantages:

  • Command Line Interface
  • Menu-driven Interface
  • Graphical User Interface
  • Touchscreen Graphical User Interface

Command Line Interface

The command line interface is no longer common as a form of basic user interface in everyday consumer products, but it is still in use under certain circumstances. Command Line Interface requires users to type appropriate instructions into the command line. The computer is commanded to first go to the required file or directory. From there, a whole host of commands become available, from retrieving files to running programs.


  • Simple structure
  • Minimal memory usage
  • Great for slow-running computers, or those low on memory
  • An expert CLI user can give commands and perform tasks much faster than when using an alternative UI type


  • Difficult to learn command language
  • Complex for novice users
  • Minimal error message information

Menu-Driven Interface

The menu-driven user interface provides you with a range of commands or options in the form of a list or menu displayed in full-screen, pop-up, pull-down, or drop-down. An ATM is an example of a menu-driven interface.


  • It is not necessary to remember a long list of manual commands
  • Simple interface for novices
  • Self-explanatory menu options


  • Slower for experienced users
  • Limited menu options
  • Often requires you to access multiple menu screens to perform simple functions

Graphical User Interface

The graphical user interface, or GUI, is the type of interface with which the majority of people are the most familiar. You interact with these interfaces by using a mouse, tack pad, or other peripheral to point and click on graphics or icons.


  • Self-explanatory
  • Easy to use
  • Memorizing command lists is not necessary
  • Allows for running multiple applications, programs, and tasks simultaneously
  • Solid support facilities
  • The similar format among different programs adds familiarity
  • WYSIWYG makes for easy design and formatting


  • Uses large amounts of memory – although this is less of a concern as computers get more powerful

Touchscreen Graphical User Interface

The touchscreen GUI is very similar to the regular GUI, except that you use your fingers or a stylus to select icons and perform tasks, rather than a mouse or trackpad. Touchscreen GUIs are commonly found on tablets, smartphones, and medical devices, like the t:slim insulin pump. The touchscreen GUI has the same benefits and disadvantages as standard GUIs, but also offers a more intimate method of interaction. The lack of peripherals makes touchscreen GUIs very convenient.

Of the four types of user interface, the graphical user interface is by far the most common, followed by the touchscreen variation. Despite the alternative technologies that already exist and continue to emerge, the GUI remains the preferred standard. This is largely due to the simplicity and ease of use.

Graphical user interfaces are easier for most end users to understand as the icons and menus are generally self-explanatory and the GUI does not require the user to remember or input complex commands.

While they do take up considerable memory space compared to other UIs, this is a secondary concern as devices continue to have larger, more efficient storage than their predecessors.

To learn more about GUI design and development contact Altia today