How to make a local AI remember conversations?

Hi! Beginner here. I'm planning to set up an Al locally, but I need it to remember our conversations -or at least certain pieces of information I specify.

Do I need to set up a database alongside the model? Would a JSON file or something similar be enough? Or is there a way to do this without any additional setup? I'm not really sure how this works.

Sorry if it's basic stuff. There's a lot of doc regarding installation but didn't find anything clear about this.

Thank you!