IOS development refers to the process of creating applications that run on Apple's iOS operating system, which powers iPhones, iPads, and iPod Touch devices. It involves designing, coding, testing, and optimizing apps to provide engaging and valuable experiences to users in the Apple ecosystem.

Developers use programming languages like Swift and Objective-C to build iOS apps. These apps can range from entertainment and social networking to business and productivity tools. With a focus on user experience, iOS development aims to deliver seamless, intuitive, and high-performing applications.