Conversational commerce
Conversational commerce is selling through a chat interface, where a person describes what they want in their own words and is answered in conversation, rather than browsing a catalogue and navigating a storefront themselves.
It predates agentic commerce and is not the same thing. A chatbot on a storefront helps a human who has already arrived; an agent acts for someone who may never arrive at all.
The two are frequently conflated in vendor material, which matters because the remedies are opposite: one is a feature you add to your site, the other is a property of the data your site publishes.
Why it matters to a store
A store that responded to agentic commerce by installing a chat widget has bought a storefront feature for a problem that happens off the storefront. It is the commonest category error in this subject.