An orchestrator is the lead person or lead agent that breaks work into parts, sends each part to the right worker, and pulls the results back together. It owns the shape of the work rather than every hammer swing: this part goes to a research agent, this part to a coding agent, this part needs review, this part waits for the human. One agent doing everything sounds tempting, but it runs out of context, gets distracted, or over-invests in details a subagent could handle.
Picture a general contractor. Building a house, they don’t hang every sheet of drywall, run every wire, or paint every wall. They understand the whole job, know which subcontractor does which piece, check the work, and keep it moving.
Why you care
A human can be the orchestrator too: “Research the options, then come back with a recommendation before you change anything.” The hard part is delegation routing, getting the right worker the right task at the right level of detail. Too vague and the subcontractor returns the wrong thing; too tiny and you spend more time managing than working. That routing is where a multi-agent system either helps or turns into noise.