What is an AI Agent and does it exist separate from the AI model?

A user on reddit.com is questioning the concept of AI agents, particularly in the context of an October 3, 2026 Wall Street Journal article discussing AI agents acting as swarms. The user is seeking clarification on whether AI agents exist separately from AI models and if agents from different models, such as a Gemini model agent and an OpenAI model agent, can communicate with each other.

This post offers a direct, real-time query from a developer community, unlike typical news reports that summarize or analyze the topic.