Normal addresses require 1 key, or password in order to broadcast a transaction onto the network. When storing large amounts of money, it makes sense to have a second more secure wallet similar to a savings account. The idea is very similar to 2-factor authentication. The 6 digit code you get texted to prove your identity.
This is kinda the physical version of a multisignature wallet. Each lock represents the total number of signatures required. But because Bitcoin Cash is software, it is possible to set any combination. The most common is either 2-of-2 or 2-of-3; Meaning there are 2 or 3 special addresses and they require 2 keys, or passwords in order to broadcast the transaction.
With multisignature, a hacker would have to hack all of your devices at once, AND would need access to them all at the same time, AND you'd be notified of any pending transactions so you can reject them before they are broadcast and lost. If you have CoPay across multiple devices like your phone, laptop, and computer, your funds are very secure and the odds of being compromised are close to 0.
It will be easier to start this guide on your desktop first, but not required.
To make it easier, there is an Enpass template for a 2-of-3 multisignature address. Import to Enpass
Click the + sign from the home page to create a new wallet.
Select Create Shared Wallet to make a multisignature address.
Name the wallet whatever you like, I would go with either Savings Account or 2-of-3/2-of-2 Bitcoin Cash. Be sure to click the Arrow next to Coin and select BCH.
Select Show advanced options
Create a password or generate one in Enpass and save it in the Enpass field. You should rename the label to whatever device you are using.
Check off I have written it down and click Create 2-of-3 wallet (or 2-of-2 if that's what you're doing).
You will see a QR code on the next screen. You can either click it and copy the string to paste to your other devices, or you can use the camera on your phone to scan it.
Click the + sign from the home page to create a new wallet.
Click Join shared wallet
Make sure to check the Coin is set to BCH, then enter the name of your 2nd device.
Either paste your invitation code or click the icon to scan the QR code on your first device.
Select Show advanced options
Create a password or generate one in Enpass and save it in the Enpass field. You should rename the label to the second device you are using.
Click Join at the bottom.
If you went with a 2-of-2 wallet, proceed to the backup section. Otherwise, you will need to Repeat this process for your next device.
On the Home screen of your first device, Click the 2 of 3 or2 of 2 address of the wallet you just created.
Then click Wallet not backed up
Click Got It, then click I understand.
Now, open up your Enpass entry, and type the recovery phrase in the appropriate field. Rename the label as necessary.
Now back into Copay, click I've written it down and click the phrase in order.
Note that addresses for multisignature wallets look a little different. They begin with a H, instead of a C. Also, when sending a transaction, you will be creating a proposal instead of broadcasting the payment immediately. You will see the proposal appear on your other devices and they must be approved for the transaction to be valid.
Because there is a bit more friction in sending payments out, it's a good idea to use a multisignature wallet for the bulk of your funds. The "checkings account" wallet should only be used for quick access and a small percentage of your total wealth.