ExpressionEngine has many built in add-ons, along with some downloadable ones.
The following types of add-ons are supported:
- Plugins are small run-time enhancements that affect the output of ExpressionEngine in a variety of ways.
- Modules are larger systems that can be integrated into the ExpressionEngine control panel. Almost anything that can be achieved as a stand-alone application can be designed as an ExpressionEngine module. Modules typically store content in the database and can have actions associated with them.
- Extensions are “hooks” in the system that allow information to be routed into and out of any number of points during system execution.
- Fieldtypes are types of fields that you can use in your field groups and channels.