Talk: A structured session usually done by one person. Often done in video form.
Panel: Multiple people answer questions asked by a moderator and/or from the audience.
Blog: A post on written and posted on a space that they own. (Ex. Someone posts on their own personal blog, or an employee posts on the company's blog)
Article: A piece written by an author and posted on a 3rd party site. (Ex. Gamasutra)
Tweet/Twitter Thread: Information shared on Twitter.
Newsletter: A regular source of information, usually received via email.
Other (Gaming Industry): Other useful information that does not fall into the above categories, but is useful to community managers or marketing professionals and specifically about video games.
Other (Non-Gaming Industry): Sources to do with general social media, community or marketing trends, but are not specific to video games.