The Language of Digital Commerce: From Shopping Cart to Agent
A glossary of digital commerce terms is usually out of date the moment it goes online. New terms such as headless, composable or agentic commerce do not replace older ones by accident. Each one marks a real shift in technology and ownership. Anyone making a system decision gains more from understanding these shifts than from memorising the longest possible list of terms.
In short: Since the first experiments with "teleshopping" in 1979, the language of digital commerce has moved in clearly dated leaps. From the shopping cart as a technical object, through "e-business" as a management term, "omnichannel" and "headless" as architecture terms, to "agentic commerce", where the buyer itself no longer needs to be human. Every leap shifts the same underlying question: who or what actually carries out the action? A person at a screen, a system in the background, or now an AI agent? Since November 2024, a second, parallel language has appeared that was never meant for people at all: protocol names such as Model Context Protocol, Agent2Agent and Agentic Commerce Protocol, through which machines negotiate with each other how a purchase should proceed. A glossary worth anything in 2026 would need to cover both vocabularies and explain what each new term actually stands for, rather than simply being a growing list.
Teleshopping and the Shopping Cart: The Words Before the Web (1979 to 1994)
In 1979, the British inventor Michael Aldrich connected an ordinary television set to a transaction computer over a telephone line and called the result "teleshopping", shopping at a distance. The name reveals where the first technical vocabulary of digital commerce actually came from: not computer science, but television and mail-order retail. The Aldrich family archive states explicitly that the now familiar terms "e-commerce" and "e-business" did not exist yet at the time. They only emerged in the 1990s.
Five years after Aldrich's experiment, in May 1984, 72-year-old Jane Snowball from Gateshead became one of the first documented private individuals to order groceries from her local retailer through such a system. It was a B2C sale (business-to-consumer, trade with private customers), long before that abbreviation existed. The term "shopping cart" itself is also older than the web. It simply describes what people already did in a physical shop, recreated digitally. That is exactly the pattern of this early phase. The language borrowed images from the analogue world, because there was no digital grammar of its own for commerce yet.
From Shopping Cart to "E-Business": How a Software Feature Became a Boardroom Topic (1994 to 2000)
On 11 August 1994, a buyer named Phil Brandenburger purchased Sting's CD "Ten Summoner's Tales" from the online retailer NetMarket for USD 12.48, encrypted using the new SSL protocol (Secure Sockets Layer, a method for secure data transmission). It is considered the first documented, encryption-secured online transaction of any kind. It solved a problem that had held back almost every purchase intent on the web until then. Nobody wanted to send a credit card number across the internet unencrypted.
Only a few weeks earlier, on 5 July 1994, Jeff Bezos had founded the company he initially called "Cadabra" before renaming it after the South American river. Amazon went live as an online bookshop on 16 July 1995. Almost at the same time, the company Open Market filed the first patents on the electronic "shopping cart", a UI component (user interface) that became so ubiquitous that, years later, it turned into the subject of years of patent litigation, including a case against Amazon itself. A software metaphor borrowed from the supermarket had turned into a legal asset in its own right within a few years.
In 1997, IBM, under CEO Louis Gerstner, gave the whole movement a new, boardroom-ready name: "e-business", backed by a campaign worth roughly USD 500 million. The leap from the technical "shopping cart" to the strategic "e-business" marks the first major break in the language of digital commerce. A software feature became a boardroom topic almost overnight.
Omnichannel, Headless, Composable: The Language Follows the Architecture (2010 to 2020)
The term "omnichannel" was coined in 2009 by the market research team at IDC Retail Insights, in two separate reports, one by analysts Parker and Hand, another by Ortis and Casoli. It gained wider currency in marketing and retail language from around 2010. Unlike "multichannel", which only described several separate channels running side by side, "omnichannel" promised a single, channel-spanning customer experience. That expectation still serves as the benchmark for many digital commerce projects today, even though hardly any company fully delivers on it.
The next break came from system architecture. In April 2013, Dirk Hoerig, co-founder of commercetools, launched the SPHERE.IO platform and gave the underlying idea a name: "headless commerce". The name describes precisely what was new. The frontend, in effect the "head" of the system, was technically separated from the backend, so that product data and content could be delivered to any channel through an API (Application Programming Interface): the company's own online shop just as easily as an app or an in-store screen. Within a few months, large suite vendors such as SAP Hybris also adopted the term in their own marketing materials, a sign of how quickly a new digital commerce term can catch on once it precisely captures a real technical shift.
Composable commerce went a step further in 2020. Analyst firm Gartner coined the term in June that year, describing architectures where not just the frontend but the backend too consists of interchangeable, specialised services: a separate system for product catalogue, search, checkout and pricing each, instead of a single commerce suite. In the same month, commercetools, Contentstack, EPAM Systems and Valtech founded the MACH Alliance, a vendor-neutral association that bundled four principles into a shared label: microservices-based, API-first, cloud-native (run entirely from the cloud), and headless. In short, every composable architecture is also headless, but not every headless system is already composable.
Alongside the language of architecture, the language between people and systems was also changing. In 2015, Chris Messina, then at Uber, coined the term "conversational commerce" and brought it to a wide audience with his January 2016 post "2016 will be the year of conversational commerce": shopping as a conversation in a messaging app rather than a click-through journey on a website. At the time, the term looked like a footnote. Ten years later, it describes fairly precisely what agentic commerce is now about, except that a chatbot with a fixed script no longer sits at the other end of the conversation. An agent with its own capacity to act does.
The Break Since 2024: A Second Language Nobody Reads Aloud
All the terms so far have one thing in common. They were made for people, for sales conversations and tenders. Since November 2024, a second language has been forming alongside them, one that no longer makes that claim at all.
On 25 November 2024, Anthropic published the Model Context Protocol (MCP) as an open standard that lets AI models access data sources and tools in a structured way. It is the foundational layer that practically every subsequent agent protocol builds on. Less than five months later, on 9 April 2025, Google presented the Agent2Agent protocol (A2A) at Google Cloud Next, allowing differently built agents to delegate tasks to each other. In June 2025, Google handed the specification to the Linux Foundation for neutral further development. On 16 September 2025, Google presented the Agent Payments Protocol (AP2), a standard for the payment side of such purchases, together with more than 60 partner organisations from the payments industry, including Mastercard, PayPal and Coinbase. In late September 2025, OpenAI and Stripe followed with the jointly developed Agentic Commerce Protocol (ACP), which governs how an agent actually completes a purchase, initially with Etsy sellers directly inside ChatGPT. On 11 January 2026, Google announced a further, more broadly scoped standard at its NRF keynote, the Universal Commerce Protocol (UCP), developed jointly with Shopify, Etsy, Wayfair, Target and Walmart as partners covering the entire purchase journey.
Five named standards within fourteen months, each with its own acronym, none of them meant for a sales conversation. That is the real difference to "shopping cart", "omnichannel" or "headless". Those older terms explain themselves almost on their own to an attentive listener: a cart, every channel, no head. MCP, A2A, AP2, ACP and UCP explain themselves to nobody, and they were never meant to. They are specifications a system executes, not vocabulary a person needs to internalise, unless they are implementing one of these protocols directly.
How reliably this new language already works in practice is a separate question. OpenAI scaled back checkout in ChatGPT again as early as March 2026. According to Forrester analyst Emily Pfeiffer, only around 30 Shopify merchants were genuinely active by that point, held back by unresolved tax questions and incomplete product data. A new name alone does not make a working chain. A company managing its catalogue through a PIM system today, planning to connect that product data to such a standard through structured system integration at some point, does not need a new marketing glossary for that. It needs technical documentation for engineering teams, not for buyers.
Looking Ahead to 2027: Does the Human-Readable Glossary Survive?
Does the classic, human-readable glossary disappear altogether, then? Our assessment: no, but its job changes. People will keep searching for "what does headless commerce mean", and a company that provides a clear, current answer keeps gaining visibility for it. What changes is the half-life of the terms themselves. From the shopping cart (1994) to "e-business" (1997) took three years. From "headless" (2013) to "composable" (2020) took seven years. From MCP (November 2024) to UCP (January 2026) took fourteen months, for five new terms, not just one. A reference page that grows alphabetically cannot keep up with that pace. It falls behind again by the next update, no matter how carefully it is maintained.
The practical consequence is this. A glossary still worth having in 2027 works more like a change log than a dictionary, tied continuously to actual decisions rather than a fixed maintenance schedule. And it needs two separate tracks: a slower one for architecture and management terms that people understand and use in tenders, and a faster one for protocol names and data schemas that mainly concern engineering teams and follow version numbers more than definitions. For your company, that means something concrete. More important than a complete list of terms is the habit of quickly checking, for every new term, whether it is just a new word for something familiar or marks a genuine shift that affects a system decision.
Conclusion
The language of digital commerce was never accidental. From shopping cart to e-business, from omnichannel to headless and composable, from conversational commerce to the named protocols of today's agents, every new term marked a real shift in who or what actually carries out a purchase transaction. For your own company, a complete list of terms is therefore worth less than the habit of asking a single question about every new buzzword: what shift does this describe, and does it genuinely affect our systems? A glossary written once does not answer that question. Only ongoing observation does, tied to real decisions rather than an editorial calendar.
FAQ
What is the difference between "digital commerce" and "e-commerce"?
E-commerce usually refers to the pure act of buying online. Digital commerce, as we understand the term at Arcmedia, covers the entire digital value chain around it, from product data through system integration to marketing and service, not just the transaction itself.
Who coined the term "headless commerce"?
Dirk Hoerig, co-founder of commercetools, in April 2013, on the occasion of the launch of the SPHERE.IO platform.
What is the difference between headless and composable commerce?
Headless only separates the frontend from the backend. Composable commerce, a term coined by Gartner in 2020, goes further and replaces the backend too with several independent services connected through APIs, following the MACH principle (microservices, API-first, cloud-native, headless).
What is the difference between MCP, A2A and ACP?
MCP (Model Context Protocol, Anthropic, November 2024) connects an AI model to data and tools. A2A (Agent2Agent, Google, April 2025) lets differently built agents delegate tasks to one another. ACP (Agentic Commerce Protocol, OpenAI and Stripe, September 2025) governs the actual completion of a purchase between agent and merchant.
Will there still be a human-readable glossary in the future?
Yes, but with a different role. More as a continuously updated change log tied to real decisions than a reference page written once and growing alphabetically.
What should a company practically take away from this language history?
Check what real shift, in technology, ownership or audience, every new term actually marks, rather than adopting it into your own communication without question.
Are you facing an architecture or system decision where the terms change faster than your internal glossary?
Arcmedia has been supporting companies with digital commerce projects since 1995, from analysis through implementation to ongoing operations. Our experts are happy to advise you on your project.
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Sources
- Michael Aldrich Archive, "Pioneers of Online Shopping" (teleshopping 1979, first B2C order 1984)
- historyofinformation.com, Michael Aldrich
- Vice, "The Story of the Very First Thing Securely Sold on the Internet" (NetMarket/Sting, 1994)
- History.com, "Amazon is founded by Jeff Bezos" (1994/1995)
- Techdirt and Wikipedia "Shopping cart software" and "Soverain Software" (shopping cart patents from 1994)
- IBM, "Louis Gerstner" (ibm.com/history/louis-gerstner), e-business 1997
- IDC Retail Insights (Parker/Hand, Ortis/Casoli, 2009), cited via the literature review Lazaris/Vrechopoulos (ICCMI 2014), origin of the term omnichannel
- Darin Archer, "The DCAPItator", and the commercetools blog, headless commerce 2013
- Gartner (summarised via industry sources) and the MACH Alliance, composable commerce and the MACH Alliance, 2020
- Chris Messina, Medium, "2016 will be the year of conversational commerce"
- Anthropic, "Introducing the Model Context Protocol", November 2024
- Google Developers Blog, Agent2Agent protocol, April 2025
- OpenAI, "Buy it in ChatGPT", and the Stripe Newsroom, Agentic Commerce Protocol, September 2025
- Google Cloud Blog, Agent Payments Protocol (AP2), September 2025
- Google Developers Blog, Universal Commerce Protocol (UCP), January 2026
- Stripe Newsroom and Forrester (Emily Pfeiffer), Instant Checkout scaled back, March 2026
