Explanation
Service Resources are records that represent the people or equipment that perform field service tasks[199].
Permission Set Licenses are records that grant users access to specific features or apps such as Salesforce Field Service[200]. Creating one Service Resource and assigning the relevant Permission Set Licenses would allow Universal Containers to configure Salesforce Field Service to support an employee who performs the role of a Dispatcher and a Technician by creating a service resource record for the employee and assigning them the Salesforce Field Service Dispatcher and Mobile permission set licenses[201]. Creating two Service Resources and assigning them to the employee would not work because an employee can only be associated with one service resource record[202]. Creating one Service Resource and assigning the Technician and Dispatcher role would not work because roles are records that define the level of access users have to data in an organization hierarchy[203]. Creating two Skills records and assign them to the Service Resource record would not work because skills are records that define specific abilities or qualifications that service resources have and do not affect their access to features or apps[204]. References:
https://help.salesforce.com/s/articleView?id=sf.fs_service_resources_overview.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.perm_sets_license_overview.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_perm_sets_license_assign.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_service_resources_create_edit_delete.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.roles.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_skills_overview.htm&type=5