Question about Canon EF 70-300mm F/4-5.6 IS II USM

The lens is also designed for APS-C cameras. This includes the D1300. This extends the focal length by 1.6 times. This means you are closer to the object than with a Canon 5D, for example.

You are not closer to the object: in a camera with a crop factor, the chip is smaller than in a 35 mm camera or a DSLR with a full-frame sensor. The smaller light-sensitive area causes a crop of the visible image section. This reduces the angle of view. A 100mm lens is still a 100mm lens on a camera with a crop factor of 1.6, but shows the image section comparable to a 160mm lens on a full-frame camera. Hence the misleading name focal length extension.