Name the built-in utility types you use most and what each one does.

The most used utility types fall into three groups: reshaping objects, filtering unions, and reading function types.

For reshaping objects:

• Partial<T> makes every property optional. It is handy for update payloads, where you send only the changed fields.
• Required<T> makes every property required.
• Readonly<T> marks every property readonly.
• Pick<T, K> keeps only some keys.
• Omit<T, K> removes some keys.
• Record<K, V> builds an object type with keys K and values V.

For unions:

• Exclude<U, X> removes the members that can be assigned to X.
• Extract<U, X> keeps only those members.
• NonNullable<T> removes null and undefined.

For functions and promises:

• ReturnType<F> reads a function's return type.
• Parameters<F> reads a function's parameter types as a tuple.
• Awaited<T> unwraps a promise to its resolved value.

These let you build types from existing code instead of writing them twice.