How many times render will actually run in a React Component

I was going through React LifeCycle methods when I got stumbled on this:

I got confused as I am seeing render() function to run 2 times. All I know is that any function in React Life-Cycle runs only once. So, why am I seening 2 render functions here (or running 2 times). Won't it affect the memory and overuse for running 2nd time.

Also, How we know where render function would run (or at what stage) as it can run at 2 places in React Cycle. Kinldy, help clarify.

Reference:

https://gist.github.com/bvaughn/923dffb2cd9504ee440791fade8db5f9

> Mounting

At first, Reactjs will render method only once and the lifecycle would be:

constructor();
static getDerivedStateFromProps()
render();
componentDidMount();

> Updating

But as you update component state or on receiving new props will trigger
the following lifecycle:

static getDerivedStateFromProps()
shouldComponentUpdate();
render();
getSnapshotBeforeUpdate();
componentDidUpdate();

note that, returning false from shouldComponentUpdate() will not trigger render

All methods except render() are optional

For a component, the render() function obviously can run more than once for the same mount. You may refer to this table from the React docs.

From the table, it's clearly that if a component is mounted, only constructor and componentDidMount will run once (excluding componentWillUnmount which also run once when the component is unmounted), while the other lifecycle methods can run unlimited times, depends on the number of updates of that component.

Short answer is that whenever a value of state or prop will change,your render method will run until and unless you are force stopping by returning false from of the life cycle method as @Navin Gelot mentioned,then it will not run render method otherwise yes.