In Java, annotations are a form of syntactic metadata that can be added to the source code. They provide additional information about a program without affecting its operation. Annotations can be applied to various program constructs, including classes, methods, variables, parameters, and packages. The syntax for defining an annotation typically begins with the “@” symbol followed by the annotation name, such as @Override ²³.

Annotations serve multiple purposes. They can provide information to the compiler, helping to detect errors or suppress warnings. Additionally, they can be processed at compile-time or deployment-time by software tools to generate code or configuration files. Some annotations are also available for examination at runtime, allowing for dynamic behavior in applications ¹².

Java includes a set of predefined annotations, such as @Override, which indicates that a method is overriding a method from a superclass. Furthermore, developers can create custom annotations to enhance their code, allowing for more specific functionality tailored to their needs ⁴⁵.