Latin or Roman script, is a writing system used to write many modern-day languages. It is the most used writing system in the world today. It is the official script for nearly all the languages of Western Europe and of some Eastern European languages. It is also used by some non-European languages such as Turkish, Vietnamese, Malay language, Somali, Swahili and Tagalog. It is an alternative writing system for languages such as Serbian and Bosnian.

The alphabet is a writing system which evolved from a western variety of the Greek alphabet. It was the Etruscans who first developed it after borrowing the Greek alphabet, and the Romans developed it further. The sounds of some letters changed, some letters were lost and gained and several writing styles ('hands') developed. Two such styles were combined into one script with upper and lower case letters ('capitals' and 'small letters'). Modern capital letters differ only slightly from their Roman counterparts. There are few regional variations.

Letters

Original Latin alphabet 
The Latin alphabet used by the Romans:

New alphabet 
The modern version of the alphabet is used for writing many languages. Indo-European languages, especially those of Western Europe, are mostly written with the Latin alphabet. These languages include the Germanic languages (which includes English, German, Swedish, and others) and the Romance languages (which includes French, Spanish, Italian, Portuguese and others). There are of course Indo-European languages that do not use the Latin alphabet, like Greek and Russian, as well as non-Indo-European languages that do, like Vietnamese.

Nearly all languages using the Roman alphabet include diacritics, which are symbols found above or below the letters. They are used for things such as tones and pronunciation. English is the only major European language that does not have any of these marks, at least not for native words. Words taken from other languages sometimes use diacritics to make clear the correct pronunciation.

The basic alphabet uses the following letters:

Other versions 

The Roman script has fewer letters than the sounds in some of the languages that use it. Some languages make up for the lack of letters by using diacritic marks, such as ă, â, á, é, í, î, ó, ẹ, ị, ọ, ụ, ã, ả, ẻ, ỉ, ỏ, ủ, ñ, č, ď, ě, í, ň, ř, š, ș, ť, ț, ú, ů, ž and đ. In effect, this increases the number of letters in their alphabet. Languages which use some of these characters are French, Czech, Polish, Magyar (Hungarian), Romanian, Spanish, Tagalog, Vietnamese, Esperanto, and Igbo. 

Many languages changed their writing systems to the Latin script. In some countries, Europeans made native people use it. The Vietnamese language was written in Chinese characters, and there is a Chinese-based Vietnamese writing system called chu nom. However, Chinese script requires a large number of characters to be learnt before a person is truly literate. The Vietnamese government switched to the Latin alphabet in the early 20th century so they could increase the country's literacy rates. The Vietnamese kept using the Latin alphabet even after independence since it was much faster to learn than Chinese characters (chu nom). 

After the Russian Revolution, when the Russian Empire fell, the Latin alphabet in Turkic countries was started by Azerbaijan in 1918. When the Soviet Union broke up, some of its smaller languages began using the Latin alphabet. It is now used in Turkmenistan, Uzbekistan, and Azerbaijan. Kazakhstan announced in 2018 that the Latin alphabet would become the Kazakh language's main writing system.

Changing the way a language is written to Latin letters is called romanization. Many people who do not speak the language read a romanized version to know roughly how the words will sound, even if that is not the normal way to write the language. Some languages, like Chinese and Japanese, use the Latin alphabet in their languages so that they can be typed on a computer more easily. In mainland China, pinyin is the official romanization for Mandarin Chinese, and it is used to type Chinese characters on the computer by typing them phonetically. Even though many Japanese computers have kana keyboards to type Japanese on the computer, Japanese can also be typed using the Latin alphabet. Software called IME (input method editor) converts the Latin letters, called romaji in Japanese, into Japanese kana and kanji.

References

Other websites 
 Roman Alphabet -Citizendium

Alphabet, Roman