It is distinct from "Blocking a Number." When you block a specific ex-partner or spammer, your phone (or a localized database on your device) handles the rejection. Call Barring, however, is handled by the carrier’s switch. It acts as a firewall for your entire line. Common barring categories include:
💡 This is different from your SIM PIN (which unlocks the SIM card) or your Phone Passcode (which unlocks the screen). How to Change or Reset the Password call barring password