At present, there are 18 provinces of Iraq and one region. Baghdad is the national capital and lies in Baghdad Province. In formal Iraqi usage, what is called a province is properly a governorate ((muhafazat, singular - muhafazah)
The country, which was formed by Britain by merging three provinces of the Ottoman Empire, roughly splits into Shiite, Sunni and Kurdish dominated areas. Saddam Hussein, a nominal Sunni, forced Arabization onto the Kurdish areas, so the population is more mixed there although there is a Kurdistan Regional Government. Kurdistan also has significant Turkmen and Christian minorities; the former a constant area of tension with Turkey. Saddam's former stronghold is known as the Sunni Triangle.
Many have a formal prefix of al-, as in al-Anbar, but the root part is commonly used. Articles are named for the root (e.g., Anbar) although the table below shows prefixes; there are redirects with the prefix to the articles on the province.
Most, but not all provinces, have international boundaries.