Things we use every day are made of carefully designed, created, and tested subsystems. For example, a car has an engine, suspension, and air conditioner. Teams of engineers, machinists, and technicians make these subsystems the best they can be separately before combining them to create a high quality car. This is modularity in action: creating things from smaller well-designed, well-tested parts.
Liferay Portal is modular too. It comprises code modules created and tested independently and in parallel. It’s a platform on which modules and modular applications are installed, started, used, stopped, and uninstalled. Liferay’s components use the OSGi modularity standard.
These tutorials demonstrate developing OSGi services and components to customize Liferay Portal and create applications on it. As Liferay’s developers used modules to create applications, you and your team can enjoy developing your own modules, applications, and customizations in parallel.