A: Using a product key obtained from GitHub may violate Microsoft's terms and conditions, and you may face consequences, including fines or penalties.

A: You can verify the legitimacy of a product key by checking the product key on Microsoft's website or by contacting Microsoft support directly.

GitHub is a web-based platform for version control and collaboration on software development projects. It's a popular platform for developers to share and collaborate on code, and it's also used by many individuals and organizations to share and discover open-source software.

If you decide to use a product key obtained from GitHub, make sure to follow the steps outlined in this article to activate Microsoft Office 2016 Professional Plus. Alternatively, consider purchasing a legitimate product key from Microsoft or a retail store to ensure that you have a genuine and working product key.