In short, it's a meeting to vote on the leadership of the Communist Party of China. Held every five years, the event's duration is not officially reported, but the last Congress ran over eight days.
About 370 full and alternate members of the party's elite Central Committee will be elected at the Congress. Full members have voting rights and they all come from a pre-selected pool of candidates.
They are chosen by 2,287 delegates from diverse backgrounds and groups. Among them are farmers, professionals and academics.
Those participants have been pre-screened and are deemed to have "unshakable belief," "correct political stance" and "good moral quality," among others, according to state-owned China Daily. The Chinese Communist Party boasts a membership of 89 million.
At its first session, the new Central Committee will elect about 25 members of the powerful Politburo
The Politburo will then choose members of its Standing Committee, China's top leaders. The group — now headed by President Xi Jinping, who is general secretary of the Communist Party — will be unveiled next Wednesday.