File Vault

Thanks, helpful. I questioned because I have a mid-2014 Macbook Pro that needs a new battery before giving it to my wife since I bought a new Macbook Pro M1, and Apple suggests turning on Fire Vault and backing up before taking the older laptop in for battery service. I would normally just back up, and unfortunately the older Macbook Pro does not have enough memory to ever undo turning on Fire Vault unless I take a lot of items off of the home drive which would be complicated for my wife and which makes me wary in any case. I think the T2 chip gives a lot of encryption protection, enough really, on the newer Macbook Pro. Thanks for the input; the answer just isn't on the Apple support page about Fire Vault unfortunately.