I’ve been involved in VR and AR since those technologies first emerged, so with the growing interest in the metaverse, I’m often asked for explanations and definitions. People especially want to know about the capabilities and potential risks of the metaverse. With similar questions coming up again and again, I wanted to bring together some of the most useful definitions in one place. So here it goes:

In the world of immersive media, virtual reality (RV) and augmented reality (AR) are the two pillars of the field. Both terms have been around for about 30 years, with virtual reality emerging in the late 1980s and augmented reality in the early 1990s.

The key difference is where the user feels present. In virtual reality, the user feels present within a simulated environment, while in augmented reality the user feels present in a combined world of real and virtual content.

This leads to the following definitions:

Virtual reality (VR) it is an immersive and interactive simulated environment that is experienced in the first person and provides a strong sense of presence to the user.

Augmented reality (AR) it is an immersive and interactive environment in which virtual content is spatially registered in the real world and experienced in the first person, providing a strong sense of presence in a combined real/virtual space.

To achieve a true virtual reality or augmented reality experience, a user must be able to interact with virtual content in a natural and immersive way. This distinguishes virtual reality from 3D movies and 3D simulations. It also distinguishes AR from “head-up displays” (HUDS) that present non-immersive content in the user’s line of sight, such as text, data, and flat images.

For decades, virtual reality and augmented reality were the main phrases used in academia and industry, but additional words have become popular in recent years. For example, extended reality (XR) emerged to describe the full spectrum of virtual reality and augmented reality capabilities and has become a convenient catch-all for many forms of immersive media.

The term mixed reality (MR) has also become popular but it causes some confusion because it is mainly a synonym for augmented reality. Popularity took off in the mid-2010s when Microsoft released its HoloLens headset and used the phrase “mixed reality” in its marketing parlance. Since then, people often look for ways to tell the difference between AR and MR, but it’s mostly a matter of preference.

Additional confusion has arisen because some companies have marketed smart glasses using imprecise language, describing certain products as AR/MR when they are actually head-up displays that present non-immersive content in the wearer’s line of sight. Such devices can be very useful, but they cause market confusion when compared to true augmented reality glasses like Microsoft’s HoloLens and Snap’s latest Spectacles.

To add to the confusion, the word “metaverse” has become very popular recently. The word has its roots in ’90s science fiction, but it didn’t get much use until Facebook (now Meta) put its marketing muscle behind it. It can be defined as follows:

A metaverse it is a persistent and immersive simulated world that is experienced first-person by large groups of simultaneous users who share a strong sense of mutual presence. It can be completely virtual (i.e. a virtual metaverse), or it can exist as virtual content layers superimposed on the real world (i.e. an augmented metaverse).

Some believe that a metaverse must also include formal rules of conduct and a fully functional economy. While many worlds will have these features, it feels too limiting to force that condition into the definition. Similarly, some believe that all virtual and augmented worlds will be connected into a single interoperable system. metaverse, with elements shared between the underworlds. While many worlds will most likely share features and content, some will surely stand alone and still meet the definition of a metaverse.

And no, the metaverse is not a new technology. The first dedicated metaverse I experienced was There.com, which went into beta in 2001. It was impressive, even by today’s standards. This was followed by Second Life shortly after, which was also impressive and gained a large following. Another early metaverse was ActiveWorlds, which may predate the above two, although I didn’t experience it until 2006.

Of course, the metaverse platforms of decades past did not involve recent concepts like Internet 3.0 either NFT that are now part of the conversation. These new words confuse many people, so it’s also worth providing a context and explanation.

The reason Web 3.0 and NFTs are discussed in regards to the metaverse has little to do with immersion capabilities. Instead, they relate to whether metaverse data is stored centrally by platform providers (such as user data on Facebook) or whether it is stored on distributed networks (such as cryptocurrency on the blockchain). Both are viable paths to building a metaverse, but distributed networks facilitate interoperability and strengthen data privacy. Still, it will be up to the platform providers to decide which way to go.

Before continuing, it’s worth looking into NFTs, as many people incorrectly believe they are defined as “digital collectibles.” Yes, they are currently very popular for that use, but NFT is a much broader concept meant to assign ownership of digital assets.

I like to think of NFTs as similar to VIN numbers on cars. In the physical world, you and I might have a white Tesla, fresh from the factory, so they are essentially identical. We might walk to our cars in a large parking lot and get confused about who owns which. Ownership can be easily established by looking at each car’s VIN number, which is linked to its title and tracked in a variety of databases.

In the metaverse, the same thing could happen: you and I could own virtual Tesla that look identical and are parked in the same virtual parking lot. We might be confused as to who owns which. Instead of solving this with VIN numbers, many metaverse platforms will likely track such ownership using NFTs tied to each virtual car (and any other virtual items that may be owned).

I point this out because an NFT defines property regardless of collectability. Going forward, we can look back and laugh at the wild speculative NFT markets right now. Instead, we’ll appreciate that the core value of an NFT is much more mundane: clarifying which car in a virtual parking lot is yours. It can also allow you to take that virtual car from one platform to another because NFTs are decentralized.

Finally, there is one last concept that is new to some people: haptics.

The word “haptics” refers to adding a sense of touch to computing. Touch has two components: tactile sensations (ie texture and vibration) perceived through the skin and force sensations (ie weight and resistance) perceived through the muscles. Most of today’s consumer devices that provide haptic feedback focus on tactile sensations (due to cost). But hardware that also provides force sensations makes VR and AR significantly more immersive and compelling by bringing physical realism to virtual objects.

In general, immersive media is a rapidly developing field with many overlapping words and phrases. The following graphic should help clarify the language:

Consumers should be aware that many in the industry currently use these words imprecisely. Each virtual environment is not a metaverse; Every pair of smart glasses doesn’t provide an AR/MR experience, and not all virtual worlds are guaranteed to be interoperable, even if that’s a lofty goal. On the other hand, our language will surely become more precise as the market matures and consumers become more sophisticated. Until then, the definitions above can help reduce confusion.

Louis Rosenberg is a pioneer in the fields of VR, AR, and AI. In 1992 he developed the first interactive AR system (the Virtual Fixtures platform) for the US Air Force. He went on to found the first virtual reality company Immersion Corporation (1993) and took it public in 1999. He went on to found the first virtual reality company enlarged Outland Research (2004). Rosenberg earned his Ph.D. from Stanford, taught at California State University, and has been awarded more than 300 patents for his work in virtual reality, augmented reality, and artificial intelligence. He is currently the CEO of Unanimous AI, a company that amplifies group intelligence in shared environments.