The Spring Core Module provides the fundamental features needed to build any Spring application. It includes two lightweight containers, also known as Spring containers or Inversion of Control (IoC) containers:

1. BeanFactory Container (Basic container)
2. ApplicationContext Container (Advanced container, an extension of BeanFactory) Ref:

Spring contexts are also called Spring IoC containers, They are responsible for instantiating, configuring, and assembling beans by reading configuration metadata from XML, Java annotations, and/or Java code in the configuration files. Ref