There are 4 main music shows each week that hold live performances of the top performers that week. Three of these shows give an award to the "winner" of that week, which is decided by a aggregate of physical and digital sales, popularity on search portals, phone and website votes, industry critics, etc. Each show has a different way of adding all of this up, so if you win one show it doesn't mean you'll win the others. How many you win obviously has correlation to the overall performance which decides year-end awards, though those can use different systems of determining who was "the best" that year.
This atmosphere of consistent live performances for the artists currently promoting has made it quite competitive and the fan groups have taken on characteristics of sports fans. They have an official name for their fanbase, official color (at this point, should be combined to 2 like sports), official items to show their support, and learn chants which mix in seemlessly with the breaks of the song to cheer together from the crowd. If you analyze more closely, you can work out some general "divisions" of the industry, and specific rivalries (which are mostly in the minds of the fans) Groups are also easily broken down into specific roles each member focuses on, like lead singer, main singer, lead dancer, designated rapper, good looks for center position in camera shots, etc.
Performers are scouted or try out to get picked up by the agency, where they will sign a contract to only perform for them yet also get trained by the agency. There they train professionally to debut as a performer, and most often these days it is in a group, which garners its own dedicated fanbase. Speculations about new recruits, the next concept an artist will have, who will compose their song and other details are constantly going on in regard to how competitive that will make them against other artists. They are also often getting interviewed about their mindset regarding competition with upcoming promotions or looking back at how they did in previous promotion rounds, and they get a lot of love/hate for their attitude towards others depending on their response.
Most groups will have their key members that get the spotlight and are considered to somewhat carry their group because of their talent. Off the music stage, on variety shows and dramas, things are much more individualistic and performers are hired not for for years like with their music agency, but just for a few weeks for the short-run show or a guest appearance. This allows for particularly charming people to gain popularity for their group, and make them competitive even from a small and relatively unknown agency. So while the big money decides a lot of the success, there is still an element to where skill can bring them to the top.
Honestly, the more you get into it and look at the patterns of behavior and dynamics of the industry and fans, the more you see it is quite a lot like sports.