Homer’s Odyssey begins with the word ‘Man’ [Andra, from the Attic-Greek Aner, as in the English Anthropo].
One among the various derivations of the word ‘Man’ [as in the Sanskrit Manush, Manas] is as: ‘That which has Mind’.
How is ‘Man’ different say, from a Mattress? Man is different because Man alone has Mind. This has been the traditional answer since antiquity.
Man is different because Man alone ‘Thinks’.
The defining attribute of Man is his Mind. And with this Mind, Man constructs his World as Model. And its central character is his model of himself as ‘Man’.