Integration with other tools
Jira itself is a great tool; however, there are other tools from Atlassian, such as Confluence, which is used for online collaboration; Bitbucket for code repository; and Bamboo for continuous integration. Jira and most of the other tools from Atlassian talk to each other natively.
Atlassian has this ecosystem and set of integrated tools that can be used standalone but, when integrated with each other, provide a complete solution.
For example, if your organization is looking to implement DevOps practices using Atlassian tools, then you can use tools such as Bamboo, Bitbucket in conjunction with Confluence, and Jira integrated with most of them.
Apart from integrating with tools from Atlassian, Jira can also be integrated with third-party tools and that's done using either an app or an add-on, which we'll discuss in a moment, but for any other integration where you cannot find an app, there's also the possibility of using the Jira RESTful API.