What is the difference between modules, plugins, extensions, and expansions?

Paul’s answer from http://expressionengine.com/forums/viewthread/54934/

Plugin - Has its own tags, modifies or outputs text in template or custom field (formatting). Does not require installation.

Module - Has its own tags, typically has database tables, has form actions. Needs to be installed through Modules tab.

Extension - Modifies how ExpressionEngine’s underlying code works using extension hook(s). Does not have actions, can have its own database tables. Must be enabled in Extensions Manager.

Expansion - Expands what is currently possible in ExpressionEngine. Think of an expansion pack for a video game. Same game, but new abilities and powers expanding on what is already there.

Category:Development Category:EE Coding Category:Semantics