Packages are associated with workspaces, tracking access to various extensions of the Horizon product that you can make available to users belonging to your workspace.

Plugins are specific to spaces. They are governed by two main sets of APIs: the plugin API, which is a set of function calls which plugins can make to alter the functioning of a space and associated entities, and the hook API, which is a set of events which can be registered by a plugin in order to make code changes.

Plugins contain additional state and often set certain eligibility criteria for being used in a given space.

Since plugins often extend in a very complex manner the functioning of a Horizon space, plugin attachment can only occur if the space matches a format specified by a plugin.

For instance a space might require a specific table schema in order to be eligible.

Additionally, plugins may ask users for 'data mappings' of various fields. A space might be valid to attach a plugin, but might nevertheless have ambiguities regarding the mapping of plugin variables to space entities.