Judaism - is the religion that the Rabbis have formed over many centuries which they believe will get Jewish people to God. It is different in many places from what the Hebrew Bible teaches.
Not all Jewish people adhere to Judaism. For instance - I (author of this article) am Jewish because both of my parents are Jewish.
But - I do not follow the religion of the rabbis (Judaism) because I believe it is wrong about the rejection of Yeshua as Messiah and does not match up with what the Hebrew Bible teaches about the Messiah. (Note: That does not mean I do not love my people. Please do not confuse the two issues.)
So, Judaism is a religion of the Rabbis that most (but not all) Jewish people follow. And a growing number of Jewish people do not even follow Judaism today.
We prefer to follow what the Hebrew Bible teaches rather than a "religion."