ESX and ESXi : The differences and the limitations

ESXi
1. Free. No license required.
2. Extremely small footprint (32MB on memory), Fast boot up.
3. Do not have service console.
4. Actually running on a newer architecture than ESX
5. Future development will focus on ESXi.
6. Users are encouraged to deploy ESXi.
7. VCenter cannot manage free ESXi without a vSphere license as its APIs only grant read-only access.


ESX
1. vSphere license required.
2. Bigger size compared with ESXi. 2GB.
3. Has service console. Automated scripts supported.
4. works with VCenter depending on the license purchased.





Read more :
How does VMware ESXi Server compare to ESX Server?
ESXi vs. ESX: A comparison of features