Difference between ESX and ESXi

 ESX 4.1 is the last version availability of ESX server. After vSphere 5, only ESXi is available. 

Capability	ESX	ESXi
Service Console	Present	Removed
Troubleshooting performed via	Service Console	ESXi Shell
Active Director Authentication	Enabled	Enabled
Secure Syslog	Not Supported	Supported
Management Network	Service Console Interface	VMKernel Interface
vSphere web Access	Only experimental	Full managenet capability via vSPhere web client
Major Administration command-line Command	esxcfg-	esxcli
VMkernel Network Used for	vMotion,Fault Tolarance,Stoarge Connectivity	Management Network , vMotion, Fault Tolarance, Stoarge Connectivity, ISCSI port binding