Is there any difference in 4k video from a videocamera/camcorder and a photo camera from let say Canon?
Maybe. Both will provide 4k resolution assuming the appropriate resolution is selected in the preferences. Since we don't know what cameras you want to compare we don't know what other settings, like compression, codec, imaging sensor size, lens diameter, shutter speed, aperture and a few other items that can impact the captured video. Resolution is only one measurement that defines "video quality". For example, a Canon Powershot SX740 HS is a fine compact still image capture device that can get 4k video as a convenience feature. It has a small imaging sensor and small diameter lens. There are limitations on video file size and duration, potential for overheating when capturing video and poor audio options. These limitations are common for devices designed for still image capture that happen to be able to capture video as a "convenience feature". This does not mean this compact camera can't capture good 4k video, it can, but it is not a camcorder. When we jump to a camcorder or cinema camera, the limitations listed above go away. For instance, the Canon XC or XF series video capture devices. They also provide a much wider choice of frame rates, compression, resolution, and other manual controls not normally found in still image capture devices' "convenience feature" options. If the lighting is good (typically, outdoor, sunny, clear), then it will be difficult to know the capture device. But when poor lighting, depth of field requirements, adjustments to shutter speed, focus, audio choices and other things are needed, a compact camera just cant keep up. You may not need all the other stuff since we don't know your plans for use - but you asked about the resolutions differences and if you use just that single comparison, you can expect to not be always pleased with the video results you get...
Not than any normal person can detect.
the photo is still higher quality then 4k..oh well maybe its close..yeah its pretty close depending on which camera