ISIL is an acronym for the Islamic State of Iraq and the Levant, also known as ISIS (Islamic State of Iraq and Syria). It is a jihadist extremist group that emerged in the early 2010s and gained territorial control over large parts of Iraq and Syria. ISIL is known for its brutal tactics, including mass killings, beheadings, and public executions. The group has also carried out numerous terrorist attacks in various countries around the world.