ApplicationContext in Spring can be implemented in one of the following three ways...

FileSystemXmlApplicationContext : If we want to load the definitions of beans from an XML file then FileSystemXmlApplicationContext is used. The full path of XML bean configuration file is provided to the constructor.

ClassPathXmlApplicationContext : To loads the definitions of beans from an XML file in the CLASSPATH, we use ClassPathXmlApplicationContext. It is used for application context embedded in jars.

WebXmlApplicationContext : To provide configuration for a web application WebXmlApplicationContext is used. While the application is running, it is read only. But it can be reloaded if underlying application supports it.