• Stale time ( default: 0) Length of time before your data gets stale. If the data is fresh then React Query pulls the data from the cache repeatedly, without calls to the server. • refetchOnMount ( default : true ) Reload data if it is stale. The component is mounted. • refetchOnFocus( default: true ) / false / always When the user clicks on the screen it refreshes the data. • poll data • refetchInterval: (default) 2000 refreshes every two seconds • refetchIntervalInBackground <- even if browser is not in focus • Can just fetch when a button is pressed / method called. - config - to turn off the automatic behaviour. Use refetch hook to pull back the data.