What is Hamas and what does it want?

The US State Department designated Hamas a terrorist group in 1997 (Khalil Hamra/AP/PA)

Hamas, which has ruled the Gaza Strip since 2007, launched an attack inside Israel over the weekend, killing hundreds and taking others hostage. Its unprecedented breach of the border sent fighters inside border communities and military installations, shocked Israel and its allies, and raised questions about the group’s capabilities and strategy.

An Israeli soldier outside a police station that was overrun by Hamas militants on Saturday (Ohad Zwigenberg/AP/PA)