The Fujifilm X-mount is a type of interchangeable lens mount designed by Fujifilm for use in those cameras in their X-series line that has interchangeable-lenses. These lenses are designed for 23.6mm x 15.6mm APS-C sensors.
Various lens manufacturers use this mount, such as Fujinon (Fujifilm, XF and XC lenses), Carl Zeiss AG (Touit lenses), Samyang Optics, Handevision, SLR Magic, Viltrox and Zhongyi Optics. There also is an adaptor to allow compatibility with Leica M lenses and third-party options have also been announced. Additionally, a host of adapters for a range of SLR lenses are available, allowing the mounting of lenses (without autofocus or auto aperture) from Canon, Nikon, Pentax, Minolta, Contax/Yashica, Konica and more. This mount type should not be confused with the discontinued Fujica X-mount, which is not compatible with the newer X-mount without an adapter.
"By mounting the lens deeper inside the camera, closer to the sensor, the resolution is increased across the frame. Information exchange between the body and lens ensures a responsive experience at all times."