GenServer is a generic server abstraction in Elixir that allows developers to implement server processes easily. It handles common tasks such as state management, message handling, and process supervision.

GenServer, or Generic Server, is a key abstraction in Elixir that simplifies the creation and management of server processes. It is built on top of the underlying process model provided by the Erlang VM, allowing developers to define server behavior in a straightforward and consistent manner. At its core, a GenServer is a process that can maintain state, handle asynchronous messages, and perform synchronous calls. This abstraction is particularly useful for developers who need to implement services that require maintaining state across function calls. For instance, a GenServer can be used to create a simple counter that increments its state every time it receives a specific message. The state is held within the GenServer, and it can be modified through incoming messages, allowing for controlled and predictable state management. GenServers also support callbacks that allow developers to define specific actions to take on various events, such as initialization, handling calls, and managing state updates. Moreover, GenServers benefit from the supervision trees inherent in Elixir's design, which means that they can be monitored and restarted if they fail, enhancing the reliability of applications. Overall, GenServer provides a powerful and flexible way to manage server processes, enabling developers to focus on building the application logic without getting bogged down by the complexities of process management.