Jewish secularism is when someone who is Jewish does not believe or follow religious teachings, but still identifies as a part of the Jewish community and celebrates Jewish traditions and culture.
It's like if you really liked superhero movies, but you didn't actually believe that superheroes were real. You would still enjoy watching the movies and talking to other fans about them. In the same way, someone who is Jewish but doesn't believe in God or follow religious traditions might still enjoy spending time with other Jewish people, eating special Jewish foods, and celebrating Jewish holidays like Hanukkah.
Jewish secularism can be seen as a way to connect with one's cultural heritage and community, without necessarily having to believe in the religious teachings that come with it. It allows people to create their own unique relationship with their Jewish identity, based on their individual beliefs and values.