Let's discuss what exactly business logic is, in a simplified manner with a few scenarios:
Scenario 1: Let's take a very simple banking example. The common operations which a bank holder does are the deposit and withdrawal of money. Every bank has certain rules for the maintenance of a minimum balance. The account holder cannot withdraw an amount below this minimum balance. We also need to remember here that every bank has their set of rules about what will be the minimum balance, for example, SBI has 500 Rupees, HDBC and ICICI have 5,000 Rupees, and so on. The minimum balance of an account is also dependent upon what type of account you have: for example, salary accounts can be zero balance accounts. Again, these rules change from bank to bank as a part of their business policy and their tie-ups with companies. In the persistence layer, the developers will develop the code so that after every withdrawal, the updated balance, the withdrawal amount, and other details of the...