The Western Schism was a period from 1378 to 1417, when there were different people claiming to be pope, each with his own supporters. The governments of Western Europe were about evenly divided in their support, and the whole issue had very strong political ramifications.

There is a link to an article on the Western Schism below.

The Great Schism was the division of Chalcedonian Christianity into the Eastern (Greek) and Western (Latin) branches. The Great Schism began in Constantinople in 1053.

The Roman Empire divided into the Western and Eastern, with the West centered in Rome, and the East centered in Constantinople, if you are talking about the Eastern Schism. The Great Schism in the Catholic Church usually refers to the Western Schism which divided European countries over who the true Pope was.

The Great Schism of 1054 occurred among the Christians of Eastern and Western Roman Empire.

You're thinking of the Eastern Schism, sometimes called the Great Schism, but in the Catholic Church, the Great Schism refers to the Western Schism in the 15th century, not the Eastern Schism in the 11th century.