Explanation : Intension and extension indicate the reference of a term or concept. Intension indicates the internal content of a term or concept that constitutes its formal definition; while extension indicates its range of applicability by naming the particular objects that it denotes. For instance, the intension of 'vehicle' is "means for conveyance on road,"; its extension, all its kinds such as motorcycles, cars, buses, trucks, trailers, and so on.
The denotation of a word or phrase is its explicit or direct meaning, or the associations it usually elicits; while the connotation of of a word or phrase is the associated or secondary meaning suggested or implied rather than explicitly named or described.
So, as per the question, the attributes shared by all to which a term refers is connotation; and, attributes of only those objects to which it refers is the Intension.