LangChain chains are linear: A → B → C. Can't loop or branch.

LangChain chains are linear: A → B → C. Can't loop or branch. LangGraph models workflows as a directed graph with explicit state: nodes are functions/agents, edges define transitions (conditional or fixed). Supports cycles (loop back to previous steps), branching (route based on state), and state persistence for long-running tasks. Used in an enterprise AI platform for complex multi-step workflows with HITL branching.