Essentials is quite modular, the package is split up into separate jar files, this is done so that the parts of Essentials which conflict with other plugins can be easily replaced with a plugin you prefer.
We distribute essentials in two packages, 'core' and 'extra'. The core package comes with the parts of essentials people usually use, and take little extra configuration, plugins in the extra package take a little more setting up, and it's recommended that you don't blindly install them unless you know what they do.
The core modules (which all require the main essentials.jar): EssentialsChat, EssentialsSpawn, EssentialsProtect, EssentialsAntiBuild.
- Essentials The main jar handles most of the heavy lifting, in here you will find virtually all commands, signs, the economy API, and all the code which pulls the suite together.
- EssentialsChat covers the basic chat formatting component of Essentials, with this you can change the text formatting of the public chat, and handles things such as prefixes.
- EssentialsSpawn covers basic player spawning, this plugin lets you define the place people return to on death, as well as the place people initially end up when joining the server. The position can be changed ingame by a player with the correct permissions, and can be configured for everyone or per group.
- EssentialsAntiBuild is a build permissions system, this permission allows you to restrict who can build, or who can place/break what blocks. Useful for preventing players from placing lava, for example.
- EssentialsProtect is a basic world protection system, this module allows you to configure basic rules for the server to abide by, such as preventing creepers from destroying buildings, and preventing fire spread, controlling which mobs are allowed to spawn.
- EssentialsXMPP acts as a bridge between the server and the Jabber chat network, this plugin allows player chat to cross from services like GTalk and Facebook into the game, and can also be used to monitor the server for errors.
- EssentialsGeoIP provides Geographical IP lookup, that is the module can tell you roughly the location of where a player is logging in from, based on public IP databases.
Standalone modules: EssentialsGroupManager (GroupManager formerly developed by AnjoCaido)
- EssentialsGroupManager creates permissions system, this is used to create user groups for which players are part, this allows for ranks such as 'builder', 'mod', and 'admin'.
If for some reason you find that Essentials is overriding the command of your favourite plugin, you can always remove the bind from the plugin.yml file located in the essentials.jar, this will tell essentials to not even to try to bind to this command. This option should only be tried as a last resort if other avenues fail.