This site explains the key differences between vSphere 6.5 and vSphere 6.7. An overview comparison from all vSphere Versions is available here.
| vSphere 6.5 | vSphere 6.7 | vSphere 6.7 U2 | |
| Released | November 2016 | April 2018 | April 2019 | 
| Physical CPUs per host | 576 | 768 | |
| Physical RAM per host | 12 TB | 16 TB | |
| VMs per host | 1024 | 1024 | |
| vCPU per VM | 128 | 128 | 256 | 
| vMEM per VM | 6128 GB | 6128 GB | |
| Cluster Size | 64 | 64 | |
| VM Hardware Version | 13 | 14 | 15 | 
| VMFS Version | 5.81 (VMFS5) 6.81 (VMFS6)  | 
5.81 (VMFS5) 6.82 (VMFS6)  | 
|
| Management | vSphere Web Client HTML5 Client  | 
HTML5 Client vSphere Web Client  | 
|
| Platform Services Controller | Embedded PSC External PSC  | 
Embedded PSC | |
| vMotion | Cluster-wide EVC | Cluster-wide EVC Per-VM EVC vGPU vMotion  | 
|
| vMotion Network Support | L3 Network max. 100ms RTT vMotion Traffic Encryption  | 
L3 Network max. 150ms RTT vMotion Traffic Encryption  | 
|
| Fault Tolerance Support | 4 vCPU 64 GB RAM  | 
8 vCPU 128 GB RAM  | 
|
| REST API | YES (700 Operations) | YES (900 Operations) | |
| Virtual SAN | VSAN 6.5 iSCSI Support 2-node Direct Connect 512e Device Support  | 
vSAN 6.7 HTML5 Interface Support Fast Network Failover Microsoft WSFC 4k Native Device Support FIPS 140-2 Level 1  | 
|
| vCenter Type | Windows Linux (vCSA)  | 
Linux (vCSA) Windows  | 
|
| vSphere Quick Boot | NO | YES | |
| Persistent Memory | NO | YES | |
| vCSA Scale (vPostgres) | 2000 Hosts 25000 VMs  | 
2000 Hosts 35000 VMs  | 
|
| vCSA Operating System | Photon 1.0 | Photon 1.0 | |