Microsoft ended mainstream support for Windows 7 on January 13, 2015, but extended support won’t end until January 14, 2020.
Mainstream support and extended support define the amount of time Microsoft gives for its Windows operating systems – essentially, expiration dates.
When your computer’s operating system is within the mainstream support period, it means Microsoft is still taking care of that version. By taking care, we mean providing security updates for any bugs that emerge, releasing design changes and warranty claims, for example.
Microsoft usually ends mainstream support five years after the release of an operating system, which then pushes it into extended support. This period usually runs for another five years too, but you get less support. Essentially it means the company stops adding new features and ends complimentary support for that version of Windows. But it still provides bug fixes and patches.