Development of Windows 10 is a continuous process—while previous versions of Windows received service packs or point releases that served primarily as rollups of Windows Update security patches, Windows 10 receives feature updates on an approximately six month cadence. These updates bring significant user-facing changes, as well as changes to enterprise features.
Windows 10 version 1903 (also called 19H1) was made available to the Release Preview ring of the Windows Insider Program on April 8, 2019, and was added to the MSDN download catalog on April 18, 2019. General availability for consumers is expected in May 2019, though a firm release date has not been announced. Here's what you need to know.