[Question] Explanation of setStatus

[sinar93]

Hello
Sorry to bother you,
Could you please explain a little bit about setStatus and it's usage?
It's almost setStatus(null) most of places and only in login:

  useEffect(() => {
    const reset = query && query.reset ? query.reset as string : ''
    if (reset.length > 0 && errors.length === 0) {
      setStatus(atob(reset))
    } else {
      setStatus(null)
    }
  }, [query, errors])

Many Thanks in advance