What is an API? Types of APIs Explained | System Design | 6

An introductory overview of APIs (Application Programming Interfaces) covering what they are and why they exist, followed by explanations of five major API types: REST (using JSON), SOAP (using XML, common in legacy systems), GraphQL (single endpoint with query language), gRPC (protocol buffers, efficient for microservices), and WebSockets (bidirectional real-time communication). Real-world examples like Google Maps integration in Uber/Zomato and chat/notification systems are used to illustrate concepts.