Just what it says. The critical patch is for IE to prevent a remote code execution vulnerability in IE 6-10. Make sure to get this one.
The vulnerability is related to phishing bringing the victim to a website where the vulnerability would be exploited. The others are patches for Office 2003 and Office for Mac to patch vulnerabilities in them.
Here’s what to expect:
Source:
http://technet.microsoft.com/en-us/security/bulletin/ms13-jun