https://techcrunch.com/2018/08/23/nikon-embraces-a-mirrorless-future-with-z-series-cameras-and-lenses/

The largest trend in photography over the last five years or so, not counting smartphones, has been the emergence and maturity of mirrorless camera systems. These operate in a very different manner from traditional SLRs, and as such market leaders with decades embedded in the latter — namely Canon and Nikon — have resisted making the shift. That changes for Nikon today with its announcement of the Z6 and Z7, which show the company is making the change wholeheartedly.

The Z series comprises both these two cameras and a new lens mount, which in many ways is the more important news for photographers. The F mount has been around for decades and boasts some of the world’s best glass. But ultimately a more or less clean break was needed, and the Z mount manages to provide that as well as solid back-compatibility for those who can’t bear to part with their old standby kit.