A bug is a software-related problem preventing your product (an app or a website) from reliable performance. Here in QA Supermarket, we use the following classification:
Functional bugs are related to the website or app functionality. Functional bugs can have different levels of severity: low, high, and critical.
Content Bugs relate to the actual website or app content such as text, labels, pictures, videos, icons, links, data, etc.
Visual Bugs appear in graphical user interfaces of websites or apps.