Protocols in Elixir are a way to achieve polymorphism by defining a set of functions that can be implemented for different data types, allowing for flexible code reuse.

Protocols are a powerful feature in Elixir that enable polymorphism and code reuse by defining a common interface that can be implemented for different data types. They allow developers to specify a set of functions that can be invoked on various data structures without having to modify those structures themselves. This is particularly useful when working with diverse data types that may need to share certain behaviors. To define a protocol, you use the defprotocol macro, where you declare the functions that will be part of the protocol. After defining a protocol, you can implement it for specific data types using the defimpl macro. This implementation associates the protocol functions with the given data type, allowing you to invoke the protocol functions seamlessly. For example, you could create a protocol for rendering different shapes (like circles, squares, etc.), where each shape implements the protocol to provide its specific rendering logic. This approach promotes cleaner and more maintainable code by allowing you to define behaviors in a modular way. Protocols also enable better code organization and flexibility, as you can add new implementations without changing existing code. By utilizing protocols, Elixir developers can create highly extensible and reusable components in their applications.