The term modular refers to a design or structure that is made up of separate, interchangeable parts. These parts can be combined in different ways to create a larger whole, and they often have specific functions within the overall system. Modularity allows for flexibility, adaptability, and ease of maintenance, as individual components can be replaced or updated without affecting the rest of the structure. The concept of modularity is commonly applied in various fields such as engineering, computer science, architecture, and even language learning.