>>3375490m43 is 2x crop from 35mm film or full frame camera. Apsc cameras usually are 1.6x (canon) or 1.5x crop. When you're normally talking about what focal distances you used to take a photo you usually state 35mm film equivalent of the lens, and everyone will know what you're talking about. If you take a shot at 20mm on your cam, it'll have same aspect ratio as taken with 40mm lens on full frame camera, 25mm will be same as 50mm, and so on.
Usually it's irrelevant, but when you're reading some literature, photography tutorials and the like in general, focal distances will always be stated for full frame focal distances. It's best to get used to converting those numbers, so you'll know what people are talking about. Another point are converted classic lenses, mirrorless cams are great at using them, but they'll act differently on crop cameras because of that crop factor. 50mm lens is normal aspect ratio lens on 35mm film camera, but if you convert it to m43 cam, it'll act as telephoto, same as 100mm cam would act on 35mm film camera.
