Amazon API Gateway is a fully managed service that makes it easy for developers to create, publish, maintain, monitor and secure APIs at any scale. APIs act as the “front door” for applications to access data, business logic, or functionality from backend services. Using API Gateway, we can create RESTful APIs and WebSocket APIs that enable real-time two-way communication applications. API Gateway also supports containerized and serverless workloads as well as web applications.

So we can say that, we can create, deploy, and manage a RESTful APIs in order to expose backend HTTP endpoints, AWS Lambda functions, or other AWS services with using Amazon API Gateway.

API Gateway creates RESTful APIs that are HTTP-based. And enable stateless client-server communication and also implement standard HTTP methods such as GET, POST, PUT, PATCH, and DELETE.

There are 3 main types of APIs in Amazon API Gateway;

HTTP API

REST API

Websocket API

https://medium.com/aws-lambda-serverless-developer-guide-with-hands/amazon-api-gateway-main-features-and-core-concepts-980e8cadef09