For older versions of Windows and Internet Explorer, the HTTP 1.1. specification that limits the number of concurrent connections between a browser (agent) and a host web server to 2. Microsoft took this to heart which can cause significant performance degradation which Firefox and others took advantage of by ignoring the specification.
When the ActiveX control is enabled, it will update the user's registry setting that can override the 2 connection limit. Note that this functionality isn't needed with recent versions of Internet Explorer, and also when using the full webServicesLevel, the FVTerm emulator only needs 2 connections.
Example:
<add key="httpConnections" value="9"/>
Will set the maximum HTTP connections to 9.