Mobile Development is the practice of creating software and applications for mobile devices, using various programming languages and frameworks. Coursera's Mobile Development catalogue teaches you about the key aspects of both Android and iOS development, including programming with Swift, Kotlin, and Java. You'll learn about UI design for mobile platforms, handling user input, implementing navigation, accessing remote APIs, and managing application lifecycle and data persistence. This will equip you with the capability to create responsive and user-friendly mobile apps, making you invaluable in the tech industry.