Projects: giving Claude standing context
A Project in Claude.ai is a workspace that holds a set of custom instructions and reference material, like style guides, background documents, or key facts, that apply automatically to every conversation started inside it, instead of you re-explaining that context every single time. If you're consistently working on the same kind of task, say, drafting content in a specific brand voice, or working from the same set of reference documents, a Project means you set that context up once and every new conversation in it starts already knowing it.
This is different from just pasting the same instructions into every chat, because it also keeps related conversations grouped together and separates that context from unrelated work. A Project for client A's writing style won't leak into a conversation you're having about client B, because they live in separate workspaces with their own separate context.