Wildcards in Java are a powerful feature of the Java Generics framework that allows developers to write flexible and reusable code. Represented by the “?” symbol, wildcards enable the creation of methods and classes that can operate on collections of various types without compromising type safety. There are three main types of wildcards: unbounded wildcards, which accept any type; upper-bounded wildcards, which restrict the type to a specific class or its subclasses; and lower-bounded wildcards, which allow for a specific class or its superclasses. Understanding wildcards is essential for effective use of Java’s generics.