Compared to Other VMware Consoles

The HTML Console is not the only VMware virtual machine console.
The HTML Console SDK is a tool that customers and developers can use to implement remote virtual machine access in a Web application. It differs from earlier remote consoles, and ones built into vSphere.

Compared to the VMRC SDK Plug-in

With the release of vSphere 5.1 in 2012, the VMware Remote Console (VMRC) provided a way to insert a virtual machine console into a Web application. On Windows, the VMRC SDK contained an executable Win32 plug-in for Internet Explorer. On Linux, the SDK contained a 32-bit or 64-bit NPAPI shared object for Mozilla Firefox and Google Chrome. NPAPI was the Netscape plug-in API, now discontinued.
Due to the discontinuation of NPAPI and decreased use of Internet Explorer, alternatives were needed. The final VMRC release was for vSphere 6.0 in 2015.

Compared to vSphere Web Client Consoles

In the vSphere Web Client view of a virtual machine, Summary tab, click the small image of a console to open a browser tab showing a full image of the console screen. If the console is larger than your browser, scroll bars appear. This remote console implementation is similar to WebMKS, but not identical.
In the vSphere Web Client view of a virtual machine, click
Launch Remote Console
to open a stand-alone application for Windows, Mac OS X, or Linux. VMRC appears on upper left in the title bar. This application is not the discontinued VMRC SDK, but is descended from the remote console on VMware Workstation. The stand-alone VMRC offers features not available in the browser console, such as power operations and device management.