This documentation refers to many primitive data types which are described here to give you a full description over used data types.
Please note that some data types may not require a value, so called nullable. It means it can be a null reference.
Text represented as a series of Unicode characters. Can be null reference naturally.
Guid (globally unique identifier)
128-bit data structure that is typically used when global uniqueness is required.
Sometimes you can meet a term called “Guid empty” which refers to a Guid where all bits equal to zero. When represented as a String, it is “00000000-0000-0000-0000-000000000000”.
32-bit signed Integer.
128-bit signed Decimal number. Typically used for a prices.
ISO 8601 standard representation of the Date and Time.
Bit with two possible values – true, false.