What is the difference between Latent and Masked Defect?

Latent defects are defects which remain in the system, however, identified later. They remain in the system for a long time. The defect is likely to be present in various versions of the software and may be detected after the release.
E.g. February has 28 days. The system could have not considered the leap year which results in a latent defect
Masked defect hides other defects in the system. E.g. there is a link to add employee in the system. On clicking this link you can also add a task for the employee. Let’s assume, both the functionalities have bugs. However, the first bug (Add an employee) goes unnoticed. Because of this the bug in the add task is masked.