Hello @Kashish Yadav
Thank you for reaching out.
A user Story is just one of the many issue types you have in Jira by default, together with Tasks, Bugs, and many others. You can check the documentation below for more details about issue types:
The only difference between this issue type and the other ones is that Stories are configured with the Story Points field by default, which can be used to measure the effort needed to complete a Story compared to other work in the sprint. You can check the documentation below to know more details about this field:
Let us know if you have any questions.