The conflict between Israel and Palestine began during the middle of 20th century. Israel has been occupying West Bank and Gaza Strip for over 50 years, parts of which have been claimed by Palestine as their own.
Israel has made peace with many of its neighbors but the conflict with Palestine is unending. There are numerous issues of contention between Israel and Palestine, some of which include management of water rights, the freedom movement of Palestine and control over Jerusalem.

The root cause
The conflict in the region has its roots in the formation of nationalist movements among Arabs and Jews. The objective of formation of these movements was with the intention of attaining sovereign rights for people of the Middle East region. Both these forces came face to face in South Levant which gave birth to Palestine nationalist movement. The year was 1920 and by 1947 this conflict had escalated to the Israel-Palestine conflict which has continued, ever since.
It is not as if efforts have not been made to initiate peace in the region. Oslo summit, Camp David Summit and the Taba Summit of 2001 were conducted with the objective of ensuring peace among the both fractions but peace has eluded the region and tensions remain at an all time high.