Types of user interface

Differentiating common user interfaces

User interfaces (UI) are increasingly important to most businesses. Any company that uses a device to produce and/or sell its goods is likely leveraging a UI to control that device. There are many types of user interfaces that provide control of a device for one or more human operators, but they differ in how they’re designed, constructed, and used—especially the type of device they’re used to control. Below we explore several common UIs and how they differ.

Contact us
Industrial user interface to control a large piece of equipment
smart phone with GUI to control appliances

Graphical user interface

A graphical user interface (GUI) is a digital interface that allows a user to perform commands on a connected computer or electronic device using icons and other digitally created visuals. Often, input is provided by an external device, such as a mouse, keyboard, or similar, but GUIs are also used for devices like smartphones and tablets that use touch screens as the primary source of input.

A user interacts with visuals on the screen of their device to provide commands. This is often a mouse click, a finger tap, or a series of character inputs from a keyboard. Since the interface is digitally created on the screen, it’s considered a GUI. GUIs are used in both consumer and commercial applications. 

Human machine interface

HMIs allow a human operator to control a single machine or piece of equipment, guiding it to perform its necessary tasks. HMIs are most commonly used in industrial applications such as manufacturing, in which each piece of heavy-duty equipment is controlled by its own HMI. 

An HMI can take many forms, as long as it’s used to control a machine or piece of equipment. Some basic HMIs consist solely of knobs, levers, and/or buttons that a user manipulates to control the machine. Even without a screen, a human operator can control the connected machine by adjusting the HMI’s controls. 

In other instances, an HMI may actually incorporate a GUI. Many screen-based devices incorporate GUIs to produce digital visuals for the interface. Some of today’s more complex HMIs incorporate intuitive touch- and/or voice-controlled systems.  


Human Machine Interface HMI for industrial equipment
type of interface - UCI - Woman controls computer with touch screen

Human computer interface

A human computer interface, or HCI, is a UI that gives a person control of a computer. In contrast to HMIs, which control machines or equipment that are used to apply mechanical force, HCIs give people control of computers, which store and process data. With the increasing ubiquity of computers, HCIs are used across almost every industry.

It likely won’t surprise you to learn that touch screens are the most common type of HCI. Tapping, swiping, or otherwise touching a touch screen creates commands to tell the computer or electronic device what to do next. Visit our website for more information about common touch screen technologies—including resistive, capacitive, infrared (IR), and surface acoustic wave (SAW). 

Peripherals such as mice and keyboards are also considered HCIs when used to control a computer. Since most desktop computers don’t have a touch screen (yet!), they require external controllers to perform commands.

Check our blog highlighting difference between Human Machine Interfaces (HMIs) vs. Human Computer Interfaces (HCIs).


The lines can be blurry when using the terms GUI, HMI, and HCI, especially since the general public tends to use these terms interchangeably. In addition, a GUI can be a component of a machine control (for example an HMI panels) or HCI (for example a tablet). We recently designed and manufactured an interactive kiosk for a railway system; that seems it would fall under the HCI definition. However, it also accepts payments via a credit card reader and prints physical tickets. That would seem to make it fall under HMI. What do you think? 

a graphic reading supply chain terms

About NMG 

NMG has more than 85 years of experience partnering with organizations to bring their industrial, IoT, lighting, medical, telecommunications, consumer, and aerospace products to life. We solve your most complex challenges in engineering design, manufacturing, and supply chain management.  

Follow NMG 

Could your company use results like this?

We want to learn about your organization and understand your unique challenges.

Get in Touch!

We can't wait to create winning solutions with you. Please provide your information and we'll be in touch shortly.

or call 1-323-663-3971

Current customers or vendors/suppliers,
please click here for additional contact options.