No, Miro is not part of Jira.
Jira is software developed by Atlassian, a software and technology company, used to manage tasks and projects. Jira offers users tools such as bug tracking, issue tracking, and project management. While Miro is an online collaborative whiteboard platform, developed by InVision, which enables online brainstorming, ideation, and collaboration in real-time with an infinite canvas, boards, sticky notes, and many other powerful features.
Miro integrates with Jira and allows users to map out their strategies more openly, providing more visualize the relationship between various tasks, features and teams. However, the integration between Miro and Jira is optional, so it's possible to use and benefit from Miro without relying on Jira.
If you want to find out more about how Miro works with Jira, you can visit Miro's official Help Center page:
https://miro.com/help/jira-software-and-miro/