vSphere Replication is the extension to the vCenter Server, and it provides hypervisor VM replication and recovery. This replication can be used for SRM. vSphere Replication is an alternative to storage-based replication. 

When you want to use vSphere Replication, you must download and deploy the vSphere Replication appliance. This appliance provides a plugin to vSphere Web Client and a user interface for vSphere Replication. Inside is the embedded database that stores replication configuration. 

The plug-in for vSphere Replication is available in the vSphere Web Client with the following icon:

The vSphere Replication page presents a Getting Started tab with the basic concepts on how VR will work:

When everything is properly configured, you can easily select the Configure Replication... option from the menu on every VMs:

VMware vSphere Replication can be used as a standalone VM replication solution, or can be one possible part of another VMware product—SRM. 

SRM is the BC and DR solution for the customer. This solution helps you with creating test plan recovery of a VM between a protected vCenter Server site. Planned migration is possible, and you can evacuate VMs from a protected site to a recovery site.  When you want to install SRM servers you need Windows OS. When you install SRM, you install the plugin to the vSphere Web Client.  The SRM Server provides the embedded vPostgreSQL database, you can use external DB. You must install the SRM Server on a protected and recovery site, of course.

After installing SRM servers, you use the only configuration through the vCenter Web Client plugin:

The Summary tab shows all connection status and potential problems: