Question

we can get the smell of perfume sitting several meters away

Answer 1

perfume is volatile. these volatiles evaporates very fastly. volatiles carries smell along with them. when perfume is sprayed, these volatiles spread fastly. due to this, we can get the smell of perfume several metres away.

Answer 2

The perfume molecules spread out or 'diffuse' through the air. The smell becomes less concentrated but it reaches a great distance - meaning you can smell it from relatively far away :) 

Hope I helped!