Function as a Service (FaaS) is a cloud computing model that allows developers to execute code in response to events without the complexity of managing the underlying infrastructure. In FaaS, developers write individual functions that are triggered by specific events, such as HTTP requests, database changes, or file uploads. These functions are stateless and ephemeral, meaning they run only for the duration of the event and then terminate. FaaS platforms, such as AWS Lambda, Azure Functions, and Google Cloud Functions, automatically scale the function execution based on demand, ensuring efficient resource usage.

FaaS is often associated with serverless architecture because it abstracts away server management tasks, allowing developers to focus solely on writing code. This model is particularly useful for microservices, real-time data processing, and automation tasks, as it provides cost efficiency by charging only for the compute time used. Additionally, FaaS facilitates the rapid deployment and iteration of small, independent pieces of functionality, making it an essential component of modern cloud-native applications.