Windows 10 is a computer operating system by Microsoft. It is part of the Microsoft Windows family of operating systems. It was known as Threshold when it was being developed. Windows 10 was announced at a press event on 30 September 2014. It came out for personal computers on 29 July 2015. Beginning on that day, Windows 10 was available as a free upgrade for users who had Windows 7 or Windows 8.1.

Windows 10 is designed to provide a common user interface for different systems. These include desktop, laptop, and all-in-one PCs, tablet computers, smartphones, and embedded systems such as the Xbox game console. This allows each type of system to run similar programs with greater ease.

Unlike earlier versions of Windows, Windows 10 is regularly updated with new features based on user feedback, including before it was first released. This is a part of a model of delivery known as software as a service. Every half a year, Microsoft releases updates with new features. Each release has a four-digit build number (a type of version number). The first two digits refer to the year of release, and the other two digits refer to the month of release (e.g. "1903" refers to a build released in March 2019).

New or returned features

Milestones
 30 September 2014 – Windows 10 was officially announced.

2015
 21 January – Microsoft announced that most of the devices currently running at least Windows 7 SP1 or Windows 8.1 Update will get a free upgrade to Windows 10 if it is done within the first year.
 2 February – Microsoft announced a free version of Windows 10 for Raspberry Pi 2.
 2 April – New Office 2016 for Touch preview launched for Windows 10.
 18 March – The 5th official update to Windows 10 (Build 10041) since the first was introduced.
 30 March – The 6th official update to Windows 10 (Build 10049) was introduced.
 15 July - Released to manufacturing (Build 10240)
 29 July - General availability (Version 1507)
 12 November - November 2015 Update (Threshold 1, Version 1511, Build 10586)

2016
 2 August - Anniversary Update (Redstone 1, Version 1607, Build 14393)

2017
 5 April - Creators Update (Redstone 2, Version 1703, Build 15063)
 17 October - Fall Creators Update (Redstone 3, Version 1709, Build 16299)

2018
 30 April - April 2018 Update (Redstone 4, Version 1803)
 13 November - October 2018 Update (Redstone 5, Version 1809)

2019
21 May - May 2019 Update (19H1, Version 1903)
12 November - November 2019 Update (19H2, Version 1909)

2020

 27 May - May 2020 Update (20H1, Version 2004)
 19 October - October 2020 Update (20H2, Build 19042)

Versions 
Windows 10 has many versions for different uses, that have different features.

 Windows 10 Home is meant for home use. It can be used on desktop, laptop, tablet, and 2-in-1 (mix of tablet and laptop) computers.
 Windows 10 Pro is meant more for businesses. It adds features on top of Windows 10 Home and is meant for advanced users.
 Windows 10 Pro for Workstations is similar to Windows 10 Pro but is meant for workstation use. It allows more Central processing units to be used at a time.
 Windows 10 Enterprise is meant for use in IT. It adds features on top of Windows 10 Pro.
 Windows 10 Education is meant for use in schools, colleges and universities. It is the same as Windows 10 Enterprise, but it doesn't include Cortana.
 Windows 10 Mobile, which has now been discontinued, was meant for mobile devices.

References

Microsoft operating systems