Can you explain the difference between a class and an interface in object-oriented programming?

In my final year at college, I worked on a project called a Library Management System. We used classes to represent different entities like 'Book', 'Member', and 'Librarian'. Each class had its own attributes and methods, allowing us to create objects that could interact with each other. For instance, the 'Book' class had a method to check availability, while the 'Member' class had methods to borrow and return books. We also implemented an interface called 'Searchable' to define a method 'search()' that both 'Book' and 'Member' classes had to implement. This helped us ensure that any object that needed to be searchable followed the same structure, making our system more organized and easier to manage.

During my time volunteering at a local community center, I was part of a team that organized events for different age groups. We created a class called 'Event' that included details like the event name, date, and participants. Additionally, we defined an interface called 'Registerable' that included a method 'register()'. Various event types, like 'Workshop' and 'Seminar', implemented this interface, allowing us to handle registrations uniformly. This experience taught me the importance of using interfaces to maintain consistency across different components while still allowing for unique characteristics in each event type.

In my first job as a junior developer, I worked on a project that involved creating a user management system. Here, we used classes to define user roles such as 'Admin', 'Editor', and 'Viewer'. Each role class had specific permissions and methods related to their functions. We also created an interface called 'Authenticatable' that required the classes to implement methods like 'login()' and 'logout()'. This structure allowed us to add new user roles easily without changing the core logic, demonstrating the flexibility that interfaces provide in OOP. It was a practical application of the concepts I learned in college, and it helped me understand how to write scalable code.