Explanation from a
Microsoft tech about LTSC:
The Long-Term Servicing Channel (LTSC) is designed for Windows 10 devices and use cases where the key requirement is that functionality and features don’t change over time. Examples include medical systems (such as those used for MRI and CAT scans), industrial process controllers, and air traffic control devices. These devices share characteristics of embedded systems: they are typically designed for a specific purpose and are developed, tested, and certified before use. They are treated as a whole system and are, therefore, commonly “upgraded” by building and validating a new system, turning off the old device, and replacing it with the new, certified device.
We designed the LTSC with these types of use cases in mind, offering the promise that we will support each LTSC release for 10 years--and that features, and functionality will not change over the course of that 10-year lifecycle.
Differences between the Semi-Annual Channel and LTSC
As I noted above, Windows 10 devices in the Semi-Annual Channel receive twice-yearly feature updates, once in the spring and once in the fall. These updates contain new features, services, and other major changes. Security updates, optimizations, and other minor updates or patches are released every month thereafter.
To deliver on the commitment of no changes to features or functionality, a Windows 10 LTSC release does not contain any of the components of Windows 10 that may change over the life of the release. These components include Microsoft Edge (as a modern browser, it is constantly evolving to support the current modern browser web standards) as well as components/applications regularly updated via the Microsoft Store, such as Camera, Cortana, OneNote, and other modern apps that continue to advance with innovative improvements.
Internet Explorer is included in Windows 10 LTSC releases as its feature set is not changing, even though it will continue to get security fixes for the life of a Windows 10 LTSC release.
The LTSC cadence
We create a new LTSC release approximately every three years, and each release contains all the new capabilities and support included in the Windows 10 features updates that have been released since the previous LTSC release. Unlike the year-and-month terminology employed to describe Windows 10 features updates (e.g. 1703 or 1809), LTSC releases are named with a specific year, such as Windows 10 Enterprise LTSC 2016 or Windows 10 Enterprise LTSC 2019, and they align to perpetual Office releases such as Office 2019.
Each LTSC release receives 10 years of servicing and support
. During the life of a LTSC release, you can upgrade your devices to the next or latest LTSC release free of charge using an in-place upgrade, or to any currently supported release of Windows 10. Because the LTSC is technically its own SKU, an upgrade is required from Windows 10 Enterprise LTSC to Windows 10 Enterprise, which supports the Semi-Annual Channel.
As with the Semi-Annual Channel, LTSC devices receive regular quality and security updates to ensure that device security stays up to date. While quality updates are available for Windows 10 Enterprise LTSC, you can choose to defer them using tools such as Windows Update for Business or System Center Configuration Manager.