Of or relating to Jews or their culture or religion.

Jewish means belonging to the Jewish faith or religion. Jewish, for some, means going out for Chinese food on Christmas Eve.
Jewish people, historically were denied entry into many professions and guilds and were forced to be money lenders, hence the stereotype of Jews and money.
Many Jews, but not all Jews invest heavily in education. Hence, a wise person is an informed person and can learn to read and analyze stocks. There's no special magic to learning to make an investment. Read a book, dude!

Someone who is partially, but not completely Jewish. They are Jew-ish. Kinda like a Jew, but not quite.

a person who believes in Judaism/relating to the Jews

A person who follows the religion of Judaism.

Judaism is the worlds 1st monotheistic religion and has about 14,000,000 followers worldwide today. Some Notable ones include Jerry Seinfeld, Albert Einstein, Amanda Bynes, and Gene Simmons. Some Notable people with Jewish Ancestors are Nicholas Sarkozy, Gwinneth Paltrow, and Karl Marx.

Under the last 2,000 years, after the Jew's exodus from Ancient Israel, Jews spread out and eventually formed the Groups of Ashkenazim (Germanic/Russo), Sepharadim (Spaniard/Turkic), and Mizrachim (Arabic/Irani) Jews. In their years of Exodus, Jews suffered greatly from Genocide, Pogroms and Libels. The most famous example is perhaps the Holocaust, organized Adolf Hitler that killed nearly 6,000,000 Jews and over 5,000,000 other minority members. However, in 1948, Israel became independant of Great Britain, and became a land of refugee for Jews. Ever since though, Arab Nations around Israel declared war on the young nation, and kicked out over one million of their own jews. However, Israel has never been defeated by the Arabs even with the arabs help from the SSR and with the post Pahlavi regime of Iran, and even thrives today. Today, the 4 major groups of Jews are the Ashkenazim, Sepharadim, Mizrachim, and the Beta-Israel (Ethiopian Black) jews. Jews in several nations today, have also become known as professionals and have led to major breakthroughs in the arts and sciences. And even today, Jews suffer greatly out of persecution in parts of the world out of Anti Semetic incitements under the governments, and the anti Jewish outlooks of several peoples (Some examples would be many Arabs, Norwegians, several Europeans, and the Japanese).