In the good old days when I started taking pictures, basic photography had three important components which in turn controlled the three major aspects of controlling light. Firstly Camera itself, the instrument was very important and gave the user key control over many aspects of photography but the most important of them were Shutter Speed which basically let the user decide how much time the shutter remained open exposing the film in the camera to light the speed ranged from 1/8000 of a second to hours depending on your camera. The faster shutter speeds were used to freeze motion (as in sports) and slower shutter speeds were used to blur motion (as in waterfalls).
Secondly the lens, which also gave you a bevy of options but the most important was control of aperture which is an iris inside the lens whose diameter can be changed by the aperture ring to control the amount of light and depth of field. If the aperture value (denoted by a f number) was f/ 1.8 or f/1.4 then the aperture was open wide allowing a lot of light to enter the camera which also provided a very shallow depth of field in focus effectively throwing everything other than the subject out of focus (as in portraits). A large aperture number like f/16 or f/22 essentially meant that the iris was constricted down and allowed only a tiny amount of light was allowed in to the camera and also that the depth of field was huge making everything sharply in focus (as in scenic landscapes).
The third component was film and they came in various speeds (or light sensitivity), these numbers were marked on the lens cover (ISO 100, 800, 1200 etc). ISO 100 provided the sharpest and cleanest prints but needed comparatively slower shutter speeds as their light sensitivity was low and hence were mostly used by landscape photographers whose subject didn’t move and hence had the luxury of using a tripod and long exposures. A faster film say with an ISO 800 allowed the photographer to use comparatively faster shutter speeds as these films were typically more light-sensitive but their drawbacks were that the pictures were more grainier and less clean. They were mostly used for indoor sports and Astro-Photography were the constant moving of subjects often made the use of long exposures impossible.
The advent of modern digital cameras basically rendered film obsolete and replaced them with digital sensors that mimic the characteristics of film and store that information to digital media. They can be programmed in camera to change light sensitivity from ISO 100-12800 and even higher making digital cameras more complex and intimidating. Modern lenses also started providing more features like Silent Autofocus and Vibration Reduction and streamlined builds eliminating aperture control from lens and providing it through a button on the camera. There were also some disadvantages as film went out of fashion DSLR’s like any electronic products suddenly had a solid expiration date. For films when technology advanced all you need to take advantage of the new technology was to buy a new film but for digital cameras you had no such option and had to replace the camera. Also lenses while they became streamlined lost build quality and focus distance and hyper-focal markings making it extremely difficult to manually focus and thus relying on autofocus. Also consumer preferences gave rise to bulkier but slower zooms replacing light & fast fixed focal length lenses.
I personally believe while a lot of these changes are good, making products geared more towards autofocus was a bad idea as this will eventually give birth to a new breed of photographers who don’t understand the basics of manual focussing. Also cheap zoom lenses stops budding photographers from learning the basics of framing and composing a shot (they tend more to zoom than move closer, thus changing perspective). I suggest that even though you have all these luxuries available you take time to understand the basics which will help you immensely with your photography and help you appreciate what modern lenses are truly capable of doing.