This wall is called The Israel West Bank Barrier. It was created to seperate the Palestineans and Israelies.
It was built in September 2000 during the Second Intifada, a period of intensified Israel-Palestine violence.
The history of the Israel-Palestine conflict dates back to 1948 when the state of Israel was created after World War II. Then, the Palestinians and some of the Middle Eastern countries went to war with Israel because they did not agree with the new territories.
There has been several wars such as the Six-Day war in 1967 between several Arab countries and Israel. And daily conflicts, violence and disagreement between Israel and Palestine.
There are two different views to The Israel West Bank Barrier's purpose. The Isralies think of it as a way to safely seperate terrorism. The Palestineans think of it as a racial seggregation or an apartheid wall.