Project Configurator is a Jira app that can be used to transfer configuration for a group of projects from a development or test instance to another Jira instance, probably for production or integration. It can also move complete projects (including their configuration, issue data and attachments) between different instances of Jira, as needed when merging instances of Jira or archiving projects.
The app is able to handle not only the project specific configuration but also global objects such as custom fields, schemes, workflows, etc. that are referenced from the project configuration. Other global objects that are not, strictly speaking, required for a project configuration such as filters, dashboards and agile boards can also be moved. The detailed list of objects supported by the app can be seen here: Supported Types of Objects.
The XML files used to transport project configurations between Jira instances are human-readable. They do not contain ID numbers or other internal identifications, but names, descriptions and other attributes visible in the Jira user interface.