Each bug must be documented with at least one attachment. Your attachment(s) provide evidence that the bug occurs on your device, operating system, and/or browser.
Screenshot or screencast?
Functional bugs generally require a screencast to properly illustrate the issue, especially when an action triggers the bug or a process needs to be shown. Screenshots are only suitable for static issues, such as problems with the graphical user interface, and are better than video for visualization. Content or visual issues can usually be documented with just a screenshot.
What needs to be included in a screenshot?
The screenshot has to be in JPG or PNG file format. You should also Highlight the bug on your screenshot.
What needs to be included in a screencast?
Screencasts should be concise and include only the necessary steps to demonstrate the bug. Irrelevant steps, such as navigating the page where the bug occurs, can be left out. The last navigational step, the step that triggers the bug, and the bug itself are typically the only relevant steps to include.