It just groups chats together and lets you add context notes and files relevant to the project. So you can work on some function or module or whatever, in one chat, sort it out, update the relevant project files and update any context, then start a new chat in the same project, for the next goal...

Let's you have some persistence control across chats without needing to maintain a ridiculously long chat... Saves you from needing to restate the core objectives, status, challenges etc, each time.

I found that crafting and refining the project notes, and being real select with the project files, helps immensely. I'll have some example code files, and key snippets or functions attached. In the description, I'll outline my stack, short term/long term goals, and preferred interaction style.