Encrypting Android phones and data backups?

[DevilishBooster]

I did a factory reset on my G4 last night because it has been extremely sluggish the last month. I am getting more into being a "power-user" (I use that term loosely) and I started looking into Android's built in encryption function. I know that it is only "reversible" by doing a factory reset, but I can't seem to find any solid answers about backing up your data after you have encrypted it. If you encrypt your phone and then a few months later want to back up your data, does the phone being encrypted also mean that your backup data is encrypted and will be scrambled if you move to a new device later, or does it automatically get decrypted when being backed up to make sure it's readable? I'm just trying to learn as much as possible. Until a couple months ago I really only used the "basic" functions of my smartphones.