Jackson is a high-performance JSON processor for Java.
Java is a general-purpose programming language that is class-based, object-oriented, and designed to have as few implementation dependencies as possible.
The Spring Framework is an application framework and inversion of control container for the Java platform.
Spring Boot makes it easy to create stand-alone, production-grade Spring based Applications that you can "just run".
Spring Cloud provides tools for developers to quickly build some of the common patterns in distributed systems (e.g. configuration management, service discovery, circuit breakers, intelligent routing, micro-proxy, control bus, one-time tokens, global locks, leadership election, distributed sessions, cluster state).