vCenter Server Appliance 5.5 is reducing the dependency of Windows operating system for vCenter server Install. With VCSA 5.5 on Embedded database can manage 100 hosts and 3000 Virtual Machines. vCSA reduces lot of administrative efforts by reducing efforts needed for windows patching, software update and management of Guest OS on windows operating system. It is necessary to understand the difference between the vCenter Server Appliance 5.5 and vCenter server 5.5 installed on windows Server. This post will explain you the detailed difference between the 2 items.

Feature	vCenter Server Appliance 5.5	vCenter Server 5.5 on Windows
Can be Deployed	Only as a Virtual Machine	Can be installed on Physical or Virtual windows Machine
Operating System	Preconfigured Linux-based virtual machine	vCenter 5.5 requires 64 Bit OS and 64 bit DSN: Windows Server 2012 (64 bit) Windows Server 2008 Sp2 (64 bit) Windows Server 2008 R2 Sp1 (64 bit) Windows Server 2008 R2 (64 bit)
Database	PostgreSQL for the embedded database Supports Oracle Database	SQL Server 2005 (SP4) (Standard\Enterprise) (32-bit & 64-bit)SQL Server 2008 (R2 SP2, R2 SP1) (Express\standard\Enterprise\Datacenter) (32-bit & 64-bit) SQL Server 2012 (SP1) (Enterprise\Standard) (32-bit & 64-bit) Oracle 11 G Release 2 (Enterprise\Standard) & Oracle 11G ONE edition (32-bit & 64-bit)
Installation Method	Deployed as a Virtual Machine using OVF or OVA template	Need to install on top of Windows Operating System.
Hosts Per vCenter	100 Hosts with embedded vPostgres database 1000 Hosts with Oracle Database	1000 hosts per vCenter Server
Virtual Machines Per vCenter	3,000 VM’s with embedded vPostgres database 10,000 VM’s with Oracle Database	10,000 VM’s per vCenter Server
vCenter Linked Mode	Not Supported	Supported with Windows Install
vCenter Server Heartbeat	Not Supported	vCenter heartbeat is a windows application. It works with Windows install vCenter server
VMware Update Manager	You can’t install VUM on VCSA. Update Manager can be installed on separate windows machine to use with VCSA	Supported with Windows Install
AutoDeploy	Autodeploy is bundled with VCSA	Should be installed as an additional package. Installation files are located in vCenter Installation DVD
Syslog Collector	Syslog collector is installed by default	Should be installed as an additional package. Installation files are located in vCenter Installation DVD
ESXi Dump Collector Service	ESXi Dump Collector Service is installed by default	Should be installed as an additional package. Installation files are located in vCenter Installation DVD
vSphere Web Client	Pre-Installed with VCSA	Should be installed as an additional package. Installation files are located in vCenter Installation DVD
PowerCLI	Cannot be installed on vCSA	Can be installed on Windows vCenter Server machine
IPV6 support	IPv6 is not supported. Only supports IPV4	Both  IPv4 and IPv6 are supported