OS X El Capitan 10.11.4 Update 
The OS X El Capitan 10.11.4 update improves the stability, compatibility, and security of your Mac, and is recommended for all OS X El Capitan users.This update:
• Adds the ability to passcode-protect notes containing personal data in Notes• Adds the ability to sort notes alphabetically, by date created, or date modified in Notes• Adds the ability to import Evernote files into Notes• Adds support for sharing Live Photos between iOS and OS X via AirDrop and Messages• Addresses an issue that may cause RAW images to open slowly in Photos• Adds the ability for iBooks to store PDFs in iCloud, making them available across all your devices• Fixes an issue that prevented loading Twitter t.co links in Safari• Prevents JavaScript dialogs from blocking access to other webpages in Safari• Fixes an issue that prevented the VIPs mailbox from working with Gmail accounts• Fixes an issue that caused USB audio devices to disconnect• Improves the compatibility and reliability of Apple USB-C Multiport Adapters
For detailed information about the security content of this update, please visit: https://support.apple.com/kb/HT201222