The 3 options of linking Jira to Salesforce

	Remote System Reference	Remote Object Links	Remote Issue Links
Link to Salesforce
Custom display configuration
Configuration required
Workflow custom field features such as validation
Searchable in Jira
Relationship visibility in Salesforce
Data availability when Salesforce down
Synchronize to/from Salesforce
Comments synchronization
More API calls
Auto-lookup to Salesforce
Associate to multiple links in Salesforce
Associate to multiple Salesforce object types
Synchronize Remote Attachment

Classic Connector for Salesforce & Jira