The programming concept that involves grouping related properties and methods together is known as object-oriented programming (OOP). OOP centers around the concept of objects, which are instances of classes that encapsulate both data attributes and the functions (or methods) that operate on that data. This structure promotes modularity, reusability, and easier troubleshooting by organizing code into manageable pieces. Key principles of OOP include encapsulation, inheritance, and polymorphism, allowing for more efficient code management in complex applications.