Is peace possible? Israel has declared war after the country woke up to a deadly attack. It is part of a conflict that has been going on for many years.
World on high alert after Israel declares war
Boiling point: Buildings go up in smoke in Gaza as Israel vows "mighty vengeance" on Hamas. Glossary
Israeli - From Israel, a country in the Middle East. Just over 70% of its population is Jewish, while 20% is Arab.
Simchat Torah - A Jewish religious holiday in early October, celebrating the completion of the annual reading of the Torah.
Palestinian - Palestine is an area of the eastern Mediterranean region, including the West Bank, Gaza Strip and parts of modern Israel. It has been fought over by Arab and Jewish national movements for many years.
Militant - Favouring confrontational or violent methods in support of a political or social cause.
Hamas - A militant Palestinian organisation, which has controlled the Gaza Strip since 2007. It is listed as a terrorist organisation in the UK.
Gaza - The smaller of two Palestinian territories, home to two million people. It is located on the Mediterranean coast, bordered by Israel and Egypt.
Israel - A country in the Middle East, and the only Jewish nation in the modern period. It is seen by Jews, Christians and Muslims as the Holy Land.
Palestine - An area located in the Southern Levant region of Western Asia.
Gaza strip - The smaller of two Palestinian territories, home to two million people. It is located on the Mediterranean coast, surrounded by Israel and Egypt.
Blockade - Sealing off a place to prevent goods or people from entering or leaving.
Prime minister - A prime minister is the head of government in a country with a parliamentary system.