Structure in Jira

Introduction
In the latest version of Jira you can find: epics, stories, theme's and initiatives.


 * Stories: Stories, also called “user stories,” are short requirements or requests written from the perspective of an end user.
 * Epics: Epics are large bodies of work that can be broken down into a number of smaller tasks (called stories).
 * Initiatives: Initiatives are collections of epics that drive toward a common goal.
 * Themes: Themes are large focus areas that span the organization. Like knowledge sharing.

More info
See https://www.atlassian.com/agile/project-management/epics-stories-themes for more info.

Configuration
In some companies not all concepts are configured. If you need hierarchy you can to shift one level. For example your team could decide the following:
 * Tasks: should be done in one sprint
 * Userstories: more sprints
 * Epics: large focus areas for your team