The second letter of the Greek alphabet is Beta. In the Greek writing system it looks like Β in big form and β in small form. Long ago, Greeks also used letters as numbers, and beta stood for the number 2.
In Ancient Greek the letter stood for a sound like the English “b.” Today, many Greek speakers say a sound more like English “v” for the same letter. Beta is a short, useful symbol that appears in words, in number systems, and later as a symbol in science and math.