From the perspective of the diver certification agencies there is no difference between a sport diver or a recreational diver.
But we can make a difference in styles based in how the diver perceives the diving activity. The same difference of styles can be found in other sports and hobbies.
For example we can see the people that goes for a walk to a hill, there is people that wants to do this in order to have an entertaining moment with friends and families but don’t want to specialize too much on the subject and in general they will visit places with easy access and that doesn’t represent a big challenge, rather they will search for places with a nice view. On the other hand we have other type of people that also likes to go to hills but they see this activity as a sport, they tend to specialize in activities related to the hills and search not only having a good moment and a nice view but acquire a good technique and that their equipment function in the most optimal way as possible, they might even specialize in mountains.In diving we can see these different styles, there is people that just want to do a nice tour and see a beautiful view, they are not interested in transforming their hobby in a sport that requires a lot of training.
We also have divers that see diving as a sport, in the same way as who climbs a hill these divers wants that their equipment function in the most optimal way as possible, that their movements be fluent and be able to move underwater in a harmonic and efficient way. Divers that practice diving as a sport discipline seek for the exploration of new places and many times its not enough following a guide that will always lead them to the known places. When diving becomes a sport the physical condition becomes important, mental training is also a key point, the technique to move the body and the correct use of the equipment is fundamental. Every detail related with diving becomes relevant and the training becomes imperative.
As other sports, divers can specialize in different styles of diving that require specific training and in some cases the risks associated with the activity will increase together with the complexity of the activity. A diver that wants to transform this activity in a sport will get attracted to use specific equipment and to possess its own equipment with which it can familiarize at full, on the other hand a diver that only wants to go out for a tour once in a while only wants to be able to use the type of equipment that will rent in the common places that will visit.A diver that wants to get involved in the exploration of the underwater world should be able to remain more time underwater without loosing body temperature because of the cold environment. This is similar to what happens with people that climb hills, somebody that practices the activity just as a light hobby in most cases will climb the hill when there is not too much cold and the day is nice and if the temperature starts to drop they will quickly come back home. On the contrary the sportsmen won’t have problems with climbing the hill on winter even if there is ice and snow. In the case of divers, they will specialize in the use of equipment that allows diving colder waters, they will be able to remain still without the need to move in order to escape from the cold, they will learn to keep themselves warm independent of the environment temperature, in places that the water gets too cold the use of a dry suit will be a necessity.
Practicing diving as a sport doesn’t make a person a better diver, just the style is different, the style of the instructor might be different because the instructor will give importance to things that only are relevant if the activity is embraced as a sport discipline. The search for instructors that are compatible with our interests and styles is very important, this is why is always advisable to take courses with instructors of different styles, this will give the diver a wider perspective about what kind of diving wants to practice.