bank statement reconciliation matching rules-advanced matching criteria- add group

Summary:

Our client wants to understand how the functionality "add group " works under the advanced matching criteria in bank statement reconciliation matching rules. What is the functionality for "add group"? How is it different than "add condition"? If we want multiple conditions , we can create multiple conditions and use "And" operator. How will that be different from "Add group"? Please provide details about using of this functionality- "add group".