A "sura" is a chapter or section of the Quran, the holy book of Islam. There are a total of 114 suras in the Quran, each varying in length and covering different themes, such as guidance, morality, and law. The suras are traditionally recited in Arabic and are an essential part of Islamic worship and practice. Each sura is composed of verses called ayahs. The suras are often categorized into two main types: Meccan, which were revealed while the Prophet Muhammad was in Mecca, and Medinan, revealed after he migrated to Medina. This classification helps in understanding the historical context and message of each sura.