I like the idea of Background app refresh in iPhone that whenever I open back the app, I'll get new content on screen. However, can someone enlightenment me what happens if i opt not turning on background app refresh? Will the app still update its content after I reopen it, taking the possibility that now with background refresh off the app after reopening shall now take few moments to refresh its contents. Does the background refresh option affect any apps basic functionality?
With background refresh an app more or less lets iOS take care of data refresh. If this is turned off it‘s up to the application on how data gets refreshed (on activation, on user demand etc). There is no general mechanism at work then.
The 2 benefits you will get from switching "Background Refresh" off is:
It will increase your battery life.
If you are using mobile data, with "background refresh" off, it will prevent unnecessary usage of your data.
Regards to the apps actually doing the refresh when you open it, you won't even notice the difference.