Why to even create Interfaces ?

Always needed ans to this question in simple way. Thank you 🙏

Easy simple clarity 😊

why u use public key word in interfaces because Interfaces are by default Public and Abstract?

Hello sir, I have one question about inheritance. Suppose we have three entities, CEO HR and employee. These three entities must inherit each other but the fact is that data hiding feature must be implemented in each entities without using abstract keyword so at that time how we will implement inheritance my quest is that?