Copilot Studio is a Microsoft tool for building custom assistants that answer based on company sources and can trigger actions in connected systems. It falls into the category of low-code solutions, so it can also be operated by an experienced user, though deployment into production usually requires cooperation with IT. For companies that already use Microsoft's office suite and communication platform, the advantage is that the assistant can be made available directly within the environment where people work, and that existing access rights can be used. The key point is precisely the configuration of permissions – the assistant must not expose documents that the given user would not otherwise see. The quality of the answers depends on how well-organised the source documents are.
See also: RAG over a company's own content, Internal AI usage policy.