UX and UI - Two terms used interchangeably, but actually mean very different things

When it comes to product design, the tech world has abundant discussions about the great ‘UX’ of a product, or the poor ‘UI’ of a website. What is UI and UX?
At the most basic level, UI is User Interface - the series of screens, pages, and visual elements like buttons and icons that enable a person to interact with a product or service. UI design is more focused on visuals to make a product aesthetically pleasing and is more concerned with the visual properties of design and the overall feel it conveys.
UX is User Experience is the internal experience of a person while interacting with every aspect of product/service. UX design is more analytical and rooted in cognitive behavior and human psychology.
The terms UX and UI imply that they are related design disciplines, both create outstanding design solutions, but are very different. It is common for people in digital product design to use these terms interchangeably, and sometimes incorrectly too.

What is User Interface (UI)?

A user interface is a place where interactions between humans and machines occur, allowing users to effectively operate a machine to complete a task or achieve a specific goal, like making a purchase or downloading an app. Quite simply, user interface (UI) is anything a user may interact with to use a digital product or service. This includes everything from screens and touch screens, keyboards, sounds, lights. User interfaces are composed of input hardware (devices that control the machine from the human end like a keyboard, mouse, or joystick) and output hardware (devices providing information to users like monitors, audio speakers, or printers). Input devices work together with output devices so users can fully control the machine.
Essential properties of well-designed UI include
Clarity- All elements and visual metaphors are crystal clear for users and do not need to be decoded by the user.
Familiarity- Allows user to use previous experiences whilst interacting with product.
Consistency- Across products, allowing users to recognize usage patterns.
Efficiency- Allows users to provide minimal input to achieve the desired output. It also provides shortcuts for experienced users to make interaction for them more productive.

What is User Experience (UX)

UX design starts with conducting user research to understand target audience and identifying exactly what they need from the product to be designed. User personas are created to help visualize and understand goals, desires, and limitations of target users. Designers use these quantitative and qualitative user insights to iterate and improve experiences. This helps them to propose design solutions that works the best for users. Once users start interacting, their experiences (positive, negative, neutral), transform how they feel about those interactions. It is sometimes referred to as customer experience or experience design and is centered around human interaction.
UX designers invest in understanding their users through research and experimentation for which they work closely with UI designers, UX researchers, marketers, and product teams. UX designers are responsible for ensuring that the company delivers a
product/service that meets customer needs, allowing seamless achievement of their desired outcome. The multiple touchpoints with the user include:
* Process and mode of product discovery
* Sequence of actions as user interacts with interface
* Thoughts and emotions occurring in process of task accomplishment
* Impact and effect on consumer after the interaction - A mediocre UX designer will think how the user acts, an adequate one will focus on how the user thinks, a good UX designer will focus on how the user feels.