A Mem is what the mem.ai application Mem or Mem X if you subscribe, calls a note. I could have sent that answer as a Tweet. But for me, at least, it raises another question why do applications rename common terms such as a note to Mem? Surely that confuses people?
In this case, the developers are trying to sell the idea that a Mem (Note) contained with the application will help your memory, and it matches the application’s name.
I also think it ties in with Tiago Forte’s ideas of the second brain. You can read my review here, and even the ideas of the Zettelkasten system. You can learn more about Zettlekasten in my review of How to take smart notes by Sonke Ahrens.
A Mem can contain links and tags to connect your ideas, but so do Obsidian, Logseq and even Notion. Mem X in the paid-for tiers offers AI to manage these links better.
I need to test this for myself, but I doubt that having an AI managing your links can help your ideas stew and mix, allowing new ideas to come to you.
Conclusion
Sorry for the rant. I found it helpful, and I hope you did too.
You can learn more about Mem in our review. Alternatively, you might want to see how Mem compares with Obsidian as a Personal Knowledge Management system.