This is not me trying to describe every player in League of Legends, nor am I saying that every person fits into one of these categories but I think for people playing the game it is important to note the different kinds of players.
The Troll- For a lack of a better name this is the player who joins a match and then proceeds to bring down their own players. This person is often very noticeable because they are spamming the chat box about how everyone else on their team sucks, or they might target just one player. They do not understand that it is okay to lose because experience will only make someone a better player.
When you are winning by a lot this player is not likely to open their mouth, but if it is a close game and you still pull out a victory. You can expect some remarks in the after game chat room.
The Gamer- This person is here to play competitively. They are often very good players and will help carry a team to victory if everyone else can keep up. They often do not say much in the chat except a few pieces of advice that will help someone in a later game. Overall this is a very fun person to play a game with.
However there are a few who just want to win and can take losing very sorely. They can make everything into a competition and become very upset if they do poorly, or the team does poorly.
The Player- This person is there to have fun. That is all they care about win or lose as long as the game is fun they will keep on playing. Not the best player on the team, nor are they the worst. They can bring a lot to the table given a chance and will make everyone else have fun while doing it.
The Player most often suffers the wrath of The Troll.
The Beginner- They are players who play Lane specific or maybe have a few certain champions that they play. They are just getting into the game and would like to have a chance to really practice. They tend to play a lot of games versus the AI before advancing to one of the other categories or just into one of their own.
The Surrenderer- This Player hits surrender and calls for a vote as soon as the game looks like it might be lost. They continuously call for a surrender every time anything bad happens the rest of the game and harasses everyone else if they do not vote yes to surrender the match. They do not want to “waste” their time and tend to make a lot of noise about it.
Another great post about players in games like League of Legends can be found HERE. While he uses different names and mentions the AFK player all in terms to education it is still a very good summation of players.