What is API gateway? Implemented using Netflix ZUUL in Spring Boot Microservices | Code from Scratch

What is API Gateway all about? Why we should use API Gateway? Understand API Gateway with develop small project using Spring Boot with Netflix ZUUL. Github Code Location : https://github.com/binodsuman/spring_youtube Spring Dependency YouTube Playlist: https://www.youtube.com/playlist?list=PLIRnO_sdVuEfGFQ5DJfdWCrJwpCTDCDz8 Spring MVC YouTube Playlist: https://www.youtube.com/playlist?list=PLIRnO_sdVuEfGFQ5DJfdWCrJwpCTDCDz8 Spring ORM YouTube Playlist: https://www.youtube.com/playlist?list=PLIRnO_sdVuEcLDZ8m7EBa9N3D9W3bCOIm Spring AOP YouTube Playlist: https://www.youtube.com/playlist?list=PLIRnO_sdVuEebZD7qWFLe1GGT1nDtjF9Z Spring Boot YouTube Playlist: https://www.youtube.com/playlist?list=PLIRnO_sdVuEd7ooTCT6P6xraNXcweH1K0 Spring Security YouTube Playlist: https://www.youtube.com/playlist?list=PLIRnO_sdVuEfFaM65FSIz6oCD1WmgEqIL