Blue is the colour of ice, water and sky. Please fill up this album with all our blue pictures. Only sky is not enough (to much pictures) So, as less other colours in the photo as possible, but some blue things have to be seen.
Parents refers to a larger category under which an object falls. For example, theAconcagua mountain page has the 'Aconcagua Group' and the 'Seven Summits' asparents and is a parent itself to many routes, photos, and Trip Reports.