The Palestinian Islamic Jihad, usually referred to simply as Islamic Jihad is a terrorist group that was organized in the 1970's, during the first intifada, the Arab uprising against Israel.
The stated mission of Islamic Jihad the destruction of the State of Israel through holy war, and the creation of a Palestinian state in its place. The primary method employed by Islamic Jihad is suicide bombings against civilian and military targets. Islamic Jihad is funded primarily by Iran and Syria.
The Palestinian Islamic Jihad should not be confused with the Islamic Egyptian Jihad, or al-Jihad, which is also sometimes referred to as Islamic Jihad. Al-Jihad is comprised of two wings, one which operates in Egypt and was responsible for the assasination of Anwar Sadat, and another which is based in Afghanistan and is closely associated with Osama Bin Laden.
Information from the United States State Department Terrorist Group Profiles website