My question is about terminology.
Consider the following two types of definitions of a circle:
- A circle is the collection of all points at the same distance from a given point.
- A circle is the result of projecting a 3D sphere on a 2D plane and taking its convex hull.
What do you call these two types of definitions? The difference between the types is that the second definition tries to define not what the object is but rather how it is generated. Perhaps "explicit/implicit definition" (for the first/second type)? "generative definition" (for the second type)?
By the way the question is not specific to this example, but on general terminology - so I can switch examples if this one is not adequate.
An alternative more abstract example (try not to get caught on the details):
- An egg is a white (or brownish) object which has a hard shell and a soft interior with a high concentration of albumin.
- An egg is whatever the chicken lays.