One cumulative update PACKAGE for Microsoft BIZTALK Server and CONTAINS hotfixes for BizTalk Server, issues that were resolved after the release of a particular version of the BizTalk Server and includes all the component packages.
Cumulative Update package take some minutes to install, and you'll NEED to restart the server after you apply the CU.
The cumulative update should be installed on all servers that run BizTalk components.
 Important note: The cumulative update package updates only those components that are installed on the system.
In BizTalk 2013 the updates for BizTalk is pushed to regular updates, versions prior to this has to be downloaded and installed manually.

One cumulative update package for Microsoft BizTalk Server and contains hotfixes for BizTalk Server, issues that were resolved after the release of a particular version of the BizTalk Server and includes all the component packages.
Cumulative Update package take some minutes to install, and you'll need to restart the server after you apply the CU.
The cumulative update should be installed on all servers that run BizTalk components.
 Important note: The cumulative update package updates only those components that are installed on the system.
In BizTalk 2013 the updates for BizTalk is pushed to regular updates, versions prior to this has to be downloaded and installed manually.