A file is stored on disk. Visiting it in Emacs opens a buffer containing its working text; editing changes that buffer until you save. Switching to another buffer leaves the work open. Closing a buffer does not delete its file.
These tasks use ordinary text files and existing writable directories. They do not convert Word documents or PDFs into text. Start with speech working and finish any open menu or prompt. Answer a prompt and return to your work explains filename entry and the distinction between Emacs and shell input.