Where and when did the term Jew come into being><>?

The term Jew came from an area called Judah. The Hebrew word Yehudi came from Yehuda. Judah. Jews are people of Judah, technically, but the actual meaning was dropped and now mean as you see today.

Back in the day was a man by the name of Jacob. (God changed it to Isreal) He had twelve sons, one of which was named Judah. As time went by, the people of Isreal, or Hebrews as they were called in moses day would claim to be from one of these twelve tribes. Eventually most of the tribes became lost, except for parts of the tribe of Judah that returned to Jerusalem. Sometime in there they called themselves Jews. The name has stuck ever since. Sorry for the back story, I just thought it was relevent.

its called judaism because modern jews are the descendants of the kingdom of judah. 10 of the israelite tribes turned their back on the davidic monarchy and created their own kingdom, the kingdom of israel, and the rest became the kindom of judah. the kingdom of israel was completely defeated by its enemies, and so those 10 tribes were lost forever to the world (hence the mysterious "10 lost tribes of israel" thing), but the kingdom of judah continued for a bit longer and it is the kingdom that jews of today are descended from. "jew" is just the best sounding thing to call a person who follows judaism, since "judaist" sounds weird.

The first Jew was Abraham, but the term Jewish comes from the name Judah; the members of the tribe of Judah were called Jewish.

How do I know I am Jewish?

My mother was born Jewish, so was her mother, and her mother before her.

According to Jewish law, one is Jewish if their mother is Jewish or if they convert to Judaism in accordance with Jewish law.