The programming concept that refers to encapsulating data and methods within an object is called object-oriented programming (OOP). OOP organizes software design around the concept of objects, which represent real-world entities and contain both attributes (data) and behaviors (methods). This approach promotes reusability, scalability, and maintainability, allowing developers to create more modular and flexible codebases. Key principles of OOP include encapsulation, inheritance, and polymorphism, which collectively enhance the efficiency and effectiveness of software development processes.