FrontendHaltReact·Intermediate·Conceptual·1 min read
What is React reconciliation?
Short interview answer
Reconciliation is the process React uses to compare the element tree produced by a render with the previous tree and determine which host updates are needed. Rendering computes the desired UI; committing applies changes and runs commit-phase work. A component rendering does not automatically mean its DOM node changes.
Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.