Alpha and Omega are the first and last letters of the Greek alphabet, and title of Christ and God in the Book of Revelation. This couple of letters are used as Christian symbols, and are often combined with the Cross, Chi-rho, or other Christian symbols.
The Greek alphabet has been used to write the Greek language since the 8th century BC. It was derived from the earlier Phoenician alphabet, and was the first alphabetic Script to have distinct letters for vowels a well as consonants. It is the ancestor of the Latin and Cyrillic scripts.
Revelation 22:13 “I am the Alpha and Omega, the Beginning and the End, the First and the Last.