In what cases is the concept of type erasure used in programming?

Type erasure is used in programming languages with generics, such as Java, to ensure compatibility with non-generic code and to simplify execution.

In Java, for example, information about generic type parameters is removed during compilation, and only the raw type is used at runtime. This allows the same bytecode to be used for different types but imposes restrictions, such as not being able to instantiate parameterized types or check their types at runtime.

Example:

List<String> list = new ArrayList<>();
// At runtime, the JVM only sees List, without information about String

Thus, type erasure allows generics to work without increasing the size of the bytecode and maintains compatibility with existing code.