Attribute definition
An attribute definition specifies an attribute. Attribute definitions can be one of multiple types:
• Time
• Single-line text
• Multiline text
* 
Due to reasons of performance, you can only add a maximum of three attribute definitions of type Multiline text per attribute set.
• Decimal
• Date-time
• Date
• Drop-down
• Integer
You can link an attribute definition to multiple attribute sets.