HI,
enhanced license : supports one device, including all Basic devices, plus advanced (voice and video) call control features including desktop, mobile clients
Basic license : supports one device, including all Essential devices, plus basic (voice and video) call control features. (For example: Cisco 6911, Cisco 6921)
permanent license : that you order from GLO,
for more details :
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/10_0_1/ccmfeat/CUCM_BK_F3AC1C0F_00_cucm-features-services-guide-100/CUCM_BK_F3AC1C0F_00_cucm-features-services-guide-100_chapter_0100101.htmlthe above link is for 10.X but license definition and usage will be same.
Regards
Tarun