Quick Answer
In the context of a resource object (i.e., a resource represented as a JSON object), a property is a synonym, or shorthand expression, for a JSON name/value pair.
Digging Deeper
Properties are used to enumerate one or more identifying pieces of information related to the same resource object. Consider the following resource object:
{
"address":"6649 N Blue Gum St",
"city":"New Orleans",
"county":"Orleans",
"state":"LA",
"zip":"70116"
}
In the above example, we see an address property but this could also be referred to as an address name/value pair. It is perfectly acceptable to use "name/value pair" since this is how JSON is documented. However, the term property is preferred in the context of web APIs and resource objects because it defines resource object relationships better, which is evident with nested properties and sub-properties.
