Alpha, beta, gamma and delta are all Greek letters. Greek alphabet is a letter used in Greek, and it is also widely used in mathematics, physics, biology, chemistry, astronomy and other disciplines. Greek letters are similar to English letters and Russian letters, but with different symbols and the same phonetic attributes.

Greek letters are the earliest letters with vowels in the world. Cyrillic letters and Georgian letters used in Russian and Ukrainian are all developed from Greek letters, so people who have studied Russian will feel deja vu when they use Greek letters. Greek letters have entered the vocabulary of many languages. For example, the international word Delta comes from the Greek letter δ, because δ is a triangle.

The Greek alphabet comes from the Phoenician alphabet.

Phoenician letters have only consonants and are written from right to left. The vowels in Greek are developed, and the Greeks added vowels. Because the Greek writing tool was a wax board, sometimes the first line was written from right to left, and the last line was written from left to right, which became the so-called "cultivated land" writing, and then gradually evolved into all writing from left to right. The direction of the letters is also reversed. The Romans introduced the Greek alphabet, changed it into Latin alphabet with a little change, and it became popular all over the world.

Greek letters are widely used in academic fields, such as mathematics. Cyrillic letters also evolved from Greek letters. The English word alphabet (letter) comes from the alphabetum in vulgar Latin, and the alphabetum comes from the Greek word α λ φ α β ο ν (transliteration of Beton), which is the synthesis of the first two Greek letters α(Alpha) and β(Beta).