Offline payment offer another channel for both customer and you. This payment option can be used in two ways of purchase. One is normal check out from online store and another one is manual order.
To know more about manual order, please refer to this tutorial How to Handle Mail & Telephone Order?
To create offline payment method, please follow steps below
1. Go to Payment
2. Click on Activate
3. Scroll down to bottom
4. Click on Create Offline Payment Option
5. Fill in information
6. Click on Create
Example of settings display on store and manual order