From UBC Wiki

Properties are characteristics, attributes or qualities of objects.

For example, the color and mass of an object are non-relational properties because they are not in relation to anything other than the object itself, whereas weight is a relational property because it is in relation to gravity.

relational properties: properties that relate one object to another, or to a time or location.

For example, the instructor of this course has the property of being taller than a smurf, or the property of being in her office during office hours.