## Calendar API background

### Calendar concepts

Google Calendar is built on several basic concepts:

Event
:   A single event on a calendar containing information such as the title of event, start and end times, and attendees.

Calendar
:   A single calendar entry containing metadata for the calendar such as a description.

Calendar List
:   A list of all calendars on a user's calendar list in the Calendar UI.

Setting
:   A user preference from the Calendar UI, such as the user's time zone.

ACL
:   A single access control rule containing information such as the type and scope of the rule.

### Calendar API data model

A resource is an individual data entity with a unique identifier. The Calendar API operates on five types of resources:

Event Resource
:   Represents a single event on a calendar.

Calendars Resource
:   Represents metadata for an individual calendar.

CalendarList Resource
:   Represents metadata for an individual calendar that appears on the user's calendar list in the UI.

Settings Resource
:   Represents a single user preference from the Calendar UI.

ACL Resource
:   Represents an ACL.

The Calendar API data model is based on groups of resources, called collections:

Events Collection
:   Consists of all the Event Resources within a specific Calendar Resource.

CalendarList Collection
:   Consists of all the CalendarList Resources for a specific user.

Settings Collection
:   Consists of all the Settings Resources for a specific user.

ACL Collection
:   Consists of all the ACL Resources applied to a specific calendar.