Managing downloads means an extension can control files being saved to your computer, not just read your browsing. This permission is common in download managers, media savers and file organization tools, and understanding it helps you judge whether an extension's request makes sense.
What the downloads permission allows
With this permission, an extension can start new downloads, query your download history, pause, resume or cancel active downloads, and open or remove downloaded files. It gives meaningful control over files being written to your computer, beyond just viewing web pages.
Which extensions legitimately need it
Download managers, batch image or video savers, PDF tools that save files locally, and extensions that rename or sort downloads automatically need this permission because their core feature directly involves the download process. An unrelated extension requesting it deserves scrutiny.
How to check or remove the downloads permission
Open chrome://extensions, click Details on the extension to see its permissions. Chrome does not provide a separate toggle just for downloads, so if you want to revoke this access, remove the extension from the Details page or Manage extensions.