How Microsoft publishes the Windows 10 Enterprise LTSB Edition
If Microsoft has selected the feature upgrade to receive long-term servicing support, Servicing Branch #2 is used to publish the media needed to install the Windows 10 Enterprise LTSB edition. The time between releases of feature upgrades with long-term servicing support will vary between one and three years, and is strongly influenced by input from customers regarding the readiness of the release for long-term enterprise deployment. Figure 2 shows the Windows 10 Enterprise LTSB edition being published at the same time as the other Windows 10 editions, which mirrors the way editions were actually published for Windows 10 in July of 2015. It is important to note that this media is never published to Windows Update for deployment. Installations of the Enterprise LTSB edition on devices must be performed another way.
Install servicing updates only by using Long-Term Servicing Branch (LTSB) servicing
As shown in Figure 7, the Long-Term Servicing Branch (LTSB) designation refers to Servicing Branch #2 from beginning to end. LTSBs begin when a feature upgrade with long-term support is published by Microsoft and end after 10 years. It is important to note that only the Windows 10 Enterprise LTSB edition supports long-term servicing, and there are important differences between this edition and other Windows 10 editions regarding upgradability and feature set (described below in the Considerations when configuring devices for servicing updates only section).