In case anyone was wondering the actual definitions:

An edge case is a problem or situation that occurs only at an extreme (maximum or minimum) operating parameter. For example, a stereo speaker might noticeably distort audio when played at maximum volume, even in the absence of any other extreme setting or condition. [0]

A corner case (or pathological case) involves a problem or situation that occurs only outside of normal operating parameters—specifically one that manifests itself when multiple environmental variables or conditions are simultaneously at extreme levels, even though each parameter is within the specified range for that parameter. [1]

[0] https://en.wikipedia.org/wiki/Edge_case

[1] https://en.wikipedia.org/wiki/Corner_case

Take a look at polytope. Edges are easier to hit than corners. If you start in a random place and move in any direction, you will eventually hit an edge. But you might never hit a corner.