People always think that Shiv and Shankar is same, which is not true. Shiv is actually creator of Shankar. Even devotees who spend their whole life worshiping Shankar or Shiv, thinks that they are one and same. This is as common a mistake as calling our religion Hindu, whereas there is no such word in any of our religious texts. Just like we are Sanatan Dharmi, and not Hindu like popular believe, Shiv and Shankar is different and not one entity.