Modularity in programming is a software design technique that emphasizes separating the functionality of a program into independent, interchangeable modules, each containing everything necessary to execute only one aspect of the desired functionality. The goal of modular programming is to facilitate the construction of large software programs and systems by breaking them down into smaller, more manageable pieces. Each module acts like a building block, with clear and consistent interfaces and contracts, and can be tested and debugged independently. When the modules are put together, they make up the executable program. Modularity allows developers to organize their code logically, avoid repetition, and facilitate testing and debugging. It also helps in less collision at the time of working on modules, enabling a team to work with proper collaboration while working on a large application. Designing modular code requires following some basic principles and techniques, such as identifying the main functionalities and features of the program and assigning them to separate modules, defining clear and consistent interfaces and contracts for the modules, and ensuring that each module performs a logically discrete function.