No, actually the Prime Minister of Israel is the head of government of Israel and it's system of government is based on parliamentary democracy. This means that even the Prime Minister doesn't make all the decisions and rules for the country. This doesn't mean that Israel doesn't have a President, they do. Even though he has several important functions within the government, the President's role is considered ceremonial and apolitical. The government is divided in three powers, the Executive, the Legislative and the Judiciary, it's between these three powers that make all the decisions (along with the Prime Minister) in the country.