It can get a bit confusing. The below website summarizes the server releases.
https://docs.microsoft.com/en-us/windows-server/get-started/windows-server-release-info
There are two servicing models for Windows server – a long term servicing channel and a semi annual channel.
The Long Term Servicing Channel (LTSC) is like the old server releases of 2008, 2012 etc. They are major releases that are supported for a long time. While they do get security updates, they don’t get many (if any) feature updates. The idea behind these version of Windows Server is that it is stable, so it’s a good choice for your core infrastructure.
The other servicing option is is the Semi-Annual Channel (SAC). This version of Windows Server has new features, but a much shorter support period. The new features tend to be geared more towards things like Containers and Microservices – devops stuff. This version of windows is unavailable with a GUI – it is in core mode only.
Unless you need any of the features in the SAC branch (1909, 1903) then there isn’t really a need to upgrade. Nearly all of our clients are on 1809 because it is stable – only a couple have deployed 1903 or 1909 and these are for very specialised reasons.
As 1809 and 1909 are two different servicing channels, they cannot be upgraded in place.
https://docs.microsoft.com/en-us/windows-server/get-started-19/servicing-channels-19
Hope this information is helpful.
| Windows Server release | Servicing option | Editions | Availability | Build | Mainstream support end date | Extended support end date |
|---|---|---|---|---|---|---|
| Windows Server 2022 | Long-Term Servicing Channel (LTSC) | Datacenter, Standard | 2021-08-18 | 20348.169 | 2026-10-13 | 2031-10-14 |
| Windows Server, version 20H2 | Semi-Annual Channel | Datacenter Core, Standard Core | 2020-10-20 | 19042.508 | 2022-08-09 | Not applicable |
| Windows Server, version 1909 | Semi-Annual Channel | Datacenter Core, Standard Core | 2019-11-12 | 18363.418 | End of servicing | Not applicable |
| Windows Server 2019 (version 1809) | Long-Term Servicing Channel (LTSC) | Datacenter, Essentials, Standard | 2018-11-13 | 17763.107 | 2024-01-09 | 2029-01-09 |
| Windows Server 2016 (version 1607) | Long-Term Servicing Channel (LTSC) | Datacenter, Essentials, Standard | 2016-10-15 | 14393.0 | End of servicing | 2027-01-11 |
Support Dates
| Listing | Start Date | Mainstream End Date | Extended End Date |
|---|---|---|---|
| Windows Server 2019 | Nov 13, 2018 | Jan 9, 2024 | Jan 9, 2029 |
Key differences
The following table summarizes the key differences between the channels:
| Description | Long-Term Servicing Channel (Windows Server 2019) | Semi-Annual Channel (Windows Server) |
|---|---|---|
| Recommended scenarios | General purpose file servers, Microsoft and non-Microsoft workloads, traditional apps, infrastructure roles, software-defined Datacenter, and hyper-converged infrastructure | Containerized applications, container hosts, and application scenarios benefiting from faster innovation |
| New releases | Every 2–3 years | Every 6 months |
| Support | 5 years of mainstream support, plus 5 years of extended support | 18 months |
| Editions | All available Windows Server editions | Standard and Datacenter editions |
| Who can use it? | All customers through all channels | Software Assurance and cloud customers only |
| Installation options | Server Core and Server with Desktop Experience | Server Core for container host and image and Nano Server container image |