Cloud Strife first appeared in Crisis Core: Final Fantasy VII, about halfway through the game. It was for the PSP. Zack Fair met Cloud right after Tseng, the leader of the Turks, picks up Zack to go to Modeoheim for an assignment at the church in Sector 5. Zack went to the Church to visit Aerith, but Tseng tells Zack she isn't there. Cloud is one of Zack's best friends, first meeting at Modeoheim. They easily become friends because they're both "backwater(countryside) experts".
Cloud strife was introduced in FF7^^