Objective-C is an object-oriented programming language that was developed in the early 1980s and gained popularity through its adoption by Apple for macOS and iOS development. It adds Smalltalk-style messaging to the C programming language, allowing for powerful object-oriented features while maintaining the performance and low-level capabilities of C. Objective-C was the primary language used by Apple before the introduction of Swift, and it remains an important language in maintaining legacy applications and frameworks. It supports dynamic typing, runtime binding, and a unique syntax for method calls. These features make Objective-C both flexible and expressive for developers.

One of the key aspects of Objective-C is its use of classes and objects, which makes it ideal for building modular and reusable code. Developers can define classes, create instances, and send messages between objects using a distinct syntax involving square brackets. For example, [object message] is a typical message-sending format. The language also supports inheritance, encapsulation, and polymorphism, which are fundamental principles of object-oriented programming. This allows developers to write cleaner, maintainable, and scalable code. Moreover, Objective-C’s runtime system provides a high degree of dynamism, enabling developers to introspect and modify objects at runtime.