I would like to Understand [Spirituality & Religion]

It can be seen as both an ethnicity and a religion, and within the faith it may be further split by ethnicity, i.e. Ashkenazi, Sephardi, Bukhari...

There are two types of Jewish people according to the Bible. First are the descendants of Abraham and this is hereditary through physical ancestors all the way down from Abraham. They are God's chosen people according to the Old Testament. However when Jesus Christ the Messiah came many hereditary Jews sadly did not believe that He was the Son of God who had come to save them so they did not receive salvation. Since Jesus Christ came in His earthly body as a Jewish person He is a descendant of Abraham and His children that he redeemed at the cross (true born again believers in Christ and God the Father) are descendants of Abraham spiritually also (since Jesus Christ's earthly father Joseph was a descendant of Abraham). So the second type of Jewish person is spiritually Jewish and this includes Messianic Jews (physically Jewish people who are born again and believe that Jesus is the Messiah and are children of Jesus Christ) and also gentile Christian believers
(these are not born physically as direct descendants of Abraham but are spiritually Jewish since they are also Jesus Christ's children). I hope this helps you to understand what it means to be Jewish and I would like you to know that all are welcome to join God the Father's loving family. God bless you in Jesus Christ.

It's used in reference to race and their religion

Someone can be born jewish but not religious and also someone can be born not jewish but convert to the religion so..

Religion is very controversial tho