Which lens do you need for your Panasonic mirrorless camera?
Panasonic mirrorless cameras with Micro Four Thirds sensor
The mirrorless cameras from Panasonic have a Micro Four Thirds mount and sensor. You can also place lenses with an MFT mount. The sensor is smaller than full-frame and APS-C sensors, so they have a crop factor of 2. This doubles the focal length of your lens. This allows you to zoom further with your lens, which is useful to capture subjects from a long distance. Olympus has lenses with an MFT mount, just like Panasonic. That's why these Olympus lenses are also suitable for your Panasonic mirrorless camera.
Panasonic S mirrorless camera with full-frame sensor
For full-frame mirrorless cameras, Panasonic started to work together with Leica. They have made an L mount that you can find on Panasonic S cameras. On these full-frame mirrorless cameras, you can fit Panasonic S lenses. Leica and Sigma lenses are also suitable. You can switch these lenses with MFT cameras from Olympus and Panasonic.