Ease of use and intuitiveness

Using Jira is extremely intuitive and easy. Each user—whether a developer, manager, or administrator—will log in to Jira using a web browser. The moment they log in, they're presented with the Dashboard and depending upon the rights and permission of the user the appropriate features are shown and enabled for them.

Even though working on Jira is intuitive and doesn't require special training for the end user, there is, however, a learning curve. Most people who need to work on Jira learn by themselves but dedicated documentation is provided by Atlassian:

https://confluence.atlassian.com/alldoc/atlassian-documentation-32243719.html

The preceding link has the most up-to-date documentation of all of the Atlassian products including Jira Core, Jira Software, and Jira Service Desk.

Reading the documentation or a book like this one will help you quickly get started on the tool, and there are plenty of resources available to learn the tool to get the most out of it. However, if you're trying to roll out Jira in your company, then you can be assured that users can very quickly adopt it; with very short training or coaching sessions, it's very easy to introduce a tool such as Jira in your team.