Classification indicating how values are stored and represented, The system data are boolean, datetime, , float, geopoint, interger, interval, event object, string.
Boolean: True or false values.
Datetime: Specific date and time stored and displayed using the UTC time zone ("+00").
Enumeration: A list of distinct values, usually configured in a key-value pair.
Event Object: A composite data type that contains several data fields. The 'event' part indicates something that occurs and finishes, implying a certain transientness. The 'object' refers to the structure of the data associated with the attribute.
Float: High-precision fractional values.
GeoPoint: Specifies the physical location of an object such as a Place. Represents an actual point on the earth.
Integer: Whole (non-fractional) numbers.
Interval: Duration of time display as hours:minutes:seconds.
String: A combination of any characters that appear on a keyboard, such as letters, numbers and symbols.
Reference: A reference to another object in the Model.