Kali Yuga (Sanskrit: कलियुग, translit. kaliyuga, lit. ‘age of Kali’) is the last of the four stages (or ages or yugas) the world goes through as part of a ‘cycle of yugas’ (i.e. Mahayuga) described in the Sanskrit scriptures. The other ages are called Satya Yuga, Treta Yuga, and Dvapara Yuga.
Kali Yuga is associated with the demon Kali (not to be confused with the goddess Kālī). The “Kali” of Kali Yuga means “strife”, “discord”, “quarrel” or “contention”.
(from Wikipedia)