Latin alphabet
The Latin alphabet is in use today in many languages including English. It originated as the alphabet of ancient Latin, used in the Roman Empire, and has been adapted for other languages, often with the addition of diacritical marks and extra letters. It is a cousin to many other alphabets including the Greek alphabet, Cyrillic alphabet, and Hebrew alphabet, all derived ultimately from the Phoenician alphabet.
As used originally in ancient times, it had only 21 letters in it, but later on (still in Roman times) Y and Z were added on to the end, and in medieval times U and V were separated into distinct letters, as were I and J, and W was created from a doubled U or V, reaching the standard 26 letter alphabet of today which is used in English. Other languages make use of other additions beyond this. Also, lowercase letters developed in medieval times from an ancient alphabet which was all uppercase.
Many early electronic character encodings such as ASCII were derived from this alphabet and had limited repertoires outside it, while later encodings made more attempts to encompass other writing systems, culminating in Unicode.