Mapping schemes enable the administrator to manage different sets of remote system mappings and configuration.
Much like other schemes in JIRA such as notification and permissions schemes, they allow the administrator to associate specific collections of mappings to individual projects and issue types.
For example, you might want Salesforce Opportunity details to displayed for all issues in the Sales Team project, but display Salesforce Case details in the Support Team project instead. The basic workflow to put together a mapping scheme is:
Create a new mapping scheme.
Add mappings to the scheme and associate JIRA issue types with those mappings.