OS X Mavericks: If you sign out of iCloud
If you sign out of iCloud, your iCloud mail, calendars, reminders, notes, and documents stored in iCloud are removed from your Mac. If you have photos in My Photo Stream that aren’t imported, they’re removed from your Mac. Your bookmarks and Reading List remain in Safari, but iCloud Tabs are no longer available.
You can choose whether to remove your contacts, or keep a copy in your Contacts app. You can also choose whether to remove passwords and credit cards stored in iCloud Keychain, or to keep a copy in your Mac keychain. If you keep a copy of your contacts or passwords and credit cards, iCloud doesn’t keep the copy up to date with changes on your other devices.
Your other devices signed in to iCloud continue to have your most recent information. If you sign in to iCloud again on your Mac, your iCloud information reappears in your Mac apps, up to date.
Before signing out, you can open each app that has iCloud documents and save copies of those documents on your Mac. These local copies aren’t updated automatically if you use another device to change the original iCloud documents. For instructions on moving documents to iCloud, see: