Prime Or Zoom?
Whatever you're photographing from portraits to sport photography, in concept it all comes down to personal choice and how far you want to stand to get your best shot.
From a photographers eye, prime lets you escape your comfort zone and more or less take control of the exact focal length you want to use. The most common prime lens many photographers use is the 50mm f/1.8 which many people also use as their kit lens instead of the traditional 18-55 kit lens. Using a prime lens lets you explore within your photography experience into a depth that makes you want to shoot more! Using a prime lens also in a way improves your photography skills within your stance when shooting, what I mean by this is either standing up, shooting from the hip or even going out of your comfort zone to lying down on the ground to get your best shot etc... Prime also has some great features such as better larger apertures to let in more light than a zoom lens does! Larger apertures mean better blurred backgrounds for portraits and are a lot better in low light.
Many sports photographers and also including wildlife photographers use a zoom lens to get their best shots possible. Some people say "Some photographers that shoot with a zoom lens can sometimes be lazy", what people mean by this is you're just standing in one place to get your shot without exploring etc! Although zoom lens sometimes take the creation away without moving your body a lot, they sill do creative outstanding images. Even though a lot heavier than many other lenses, the purpose of this is they may have better specifications such as 'Image Stabilisation' and better focusing limitations when set to manual focus. Also, when buying a DSLR zoom lens, it all comes to price so the more you pay the faster the lens is going to be etc... Like already explained, from beginner photographers to professionals, it all comes down to personal choice.