Like other forms of removable storage media, SD cards have a "Lock" or "Write Protection" function that keeps new data from being written to the device. Enabling or disabling the lock function on an SD card is a very simple process and only takes a few seconds.
Remove the SD card from the device with which you are using it. There is no way to use the lock feature when the SD card is in use.
Slide the plastic switch on the side of the SD card down to lock the SD card. When in use, the SD card's content can be viewed, but new content cannot be written.
Slide the switch up to unlock the SD card. When a card is unlocked, data can be viewed and written to the card.
If you are using a MicroSD card, an adaptor must be used to lock and unlock the card.