Remains of Qassam rockets, fired on the Israeli town of Sderot
Gaza is a narrow strip of land, 139 square miles in area, and home to 1.8 million Palestinians, of whom 1.2 million are from refugee families. It is one of the world's most densely populated countries.
It was occupied by Egypt between 1948 and the Six-Day War, 1967.
Israel occupied the Gaza Strip in 1967 and built settlements on Palestinian land. They withdrew from the Strip in 2005 and bulldozed the settlement buildings.
Since 2007 the Gaza Strip has been governed by Hamas. Home-made Qassam rockets have been launched against Israel, which retaliated with great severity in 2008, 2012 and 2014 - see Time Line 2008-present.
Israel and Egypt now restrict crossings into and out of the Gaza Strip. The water shortage in Gaza is especially severe.