Anytime man, google can make it even more confusing, let me try! When working with different frame rates, you have to choose the frame rate for your scene and your final product. What frame rate will you ultimately be exporting in? When you upload a video to youtube, it can not have a 24 and 30 and 60fps timeline. Your video can have different clips shot at different frame rates, but they will all be converted to your chosen timeline frame rate. Lets say you shot your footage in 24fps, you pull your first clip into your timeline in your editing software, your timeline will now be 24fps. If you shot footage on your GoPro at 30fps for instance and you add that clip into your timeline, it will now also be 24fps. In effect dropping 6 of the 30 frames so that you have 24fps. If you shot in 60fps and pull that into a 24fps timeline, every 2nd or so frame is being dropped to give conform to 24fps. If you slow 60fps down to 40% that will also give you 24fps. If you slow down 120fps to 80% that will give you 24fps You want to get all your footage down to the same frame rate. That's why 30fps footage on a 24fps timeline does not work so lekka, every 4th frame is dropped and that could cause your footage to be jerky. In terms of frame rates its self: 24fps is what we are used to seeing, that is what they use in the movies. It gives a slight motion blur. If someone sits in front of the camera and waves a hand, you will pick up a slight blur in the hand. Not a lot but it is there, this is what your eyes are used to seeing. Wave your hand and look at the motion blur, you do not see all of your fingers the whole time whilst waving. 30fps will not have the same motion blur, it will be a lot smoother because there are now more fps. If you look at sports like rugby or cricket, that is shot at 60fps or even 120fps (some of the slo-mo cameras do 240fps). If cricket was shot at 24fps and a ball that was hit to the boundary, it would just be a blurry blob of a line, it moves too fast for 24fps. The image on your screen looks different compared to that of a movie when looking at sports, it is much crisper and smooth thanks to the high frame rate. BUT frame rates in live broadcast works a bit different with the 60hertz refresh rate thrown into the mix than exporting a video to youtube. (my knowledge in broadcasting is too limited to explain) Another thing to keep in mind, when there is audio with your footage, someone talking during an interview, then you definitely do not want to shoot at a different frame rate than what your main exporting frame rate is going to be. If you shot the interview in 60fps and bring that into a 24fps timeline, with every 2nd frame then being dropped, your audio will not match up to the lip movement and it will just look weird. Anyway, that's my understanding, dont take it as rule! Here is an old video but it covers the basics: