For example:
Cardinality and optionality are orthogonal properties of a relationship. You can specify that a relationship is optional, even if you have specified upper and/or lower bounds. This means that there do not have to be any objects at the destination, but if there are then the number of objects must lie within the bounds specified.
What exactly does "orthogonal" mean? I bet it's just a fancy soundig nerd-style word for something that could be expressed a lot easier to understand for average people ;)
From wikipedia:
In mathematics, two vectors are orthogonal if they are perpendicular, i.e., they form a right angle. The word comes from the Greek ὀρθός (orthos), meaning "straight", and γωνία (gonia), meaning "angle".
Anyone?
In the quoted context above you could substitute the word "independent" or "unrelated" for "orthogonal".