autogen/dotnet/website/articles/Agent-overview.md
`Agent` is one of the most fundamental concepts in AutoGen.Net. In AutoGen.Net, you construct a single agent to process a specific task, and you extend an agent using [Middlewares](./Middleware-overview.md), and you construct a multi-agent workflow using [GroupChat](./Group-chat-overview.md).  > [!NOTE] > Every agent in AutoGen.Net implements @AutoGen.Core.IAgent, for agent that supports streaming reply, it also implements @AutoGen.Core.IStreamingAgent. 