On this YouTube channel, there are a lot of competition videos with commentary.
What is the difference between the
- championship series
- challenger series
Both are LCS, aren't they?
The Challenger Series is the path that teams take to get from Challenger rank on the Ranked Ladder into the LCS. http://na.lolesports.com/articles/introducing-2014-challenger-series
The Championship series is the "actual" LCS in which teams that have made it into the LCS, such as through the Challenger Series or through having sufficient rank in the previous season's LCS, compete against each other. LCS Stands for League of Legends Championship Series. http://competitive.na.leagueoflegends.com/article/season-3-league-legends-championship-series