Spring boot is a module of spring framework which is used to create stand-alone, production-grade Spring based Applications with minimum programmer’s efforts. It is developed on top of core spring framework. The main concept behind spring boot is to avoid lot of boilerplate code and configuration to improve development, unit test etc. As in case of creating a new spring application, we have write many XML configurations, server setting, adding dependencies etc. These configuration files are one of the example of boilerplate code. Spring boot avoids all these boilerplate codes.
Spring boot architecture diagram