Part of macOS

`accountsd`Apple Account

○ Leave it

Keeps you signed in to your Apple Account and other accounts.

What it is

Manages sign-ins for iCloud, the App Store and Internet Accounts.

If you stop it

macOS starts it again straight away. Leave it.

○ Leave it. Part of macOS, or something that starts again by itself. You never need to close these.

From Procession’s guide, in the words the app shows.