You have a long recording and only one minute of it matters. Cutting it down makes it quicker to share and easier to watch.
A fast cut copies the video without encoding it again, so it takes seconds and the picture does not change at all. The cost is that it can only begin at certain points in the video, so your clip may start a moment early.
An exact cut encodes the video again so it starts precisely where you set it. It takes longer, but nothing is left to chance.
Phone videos usually allow a fast cut to land within a second or two of your choice. Screen recordings can be much looser, so for those, use the exact cut.
A fast cut starts at the nearest earlier point the video allows. Use the exact cut to start precisely.
Not in one go. Cut the part before and the part after as two clips.
No. It is cut on your own device.