How do Oracle HTTP Server and Oracle WebLogic Server work together in cluster?

Oracle HTTP Server does not require an Oracle WebLogic domain. However,

Oracle HTTP Server is typically used in conjunction with an Oracle WebLogic Domain.

mod_wl_ohs links Oracle Http Server and Oracle Weblogic Server.

In cluster, managed servers are configured together as a comma-separated list.

in mod_wl_ohs.conf file,

< Location /cs >
WebLogicCluster :16200,:16200
SetHandler weblogic-handler
WLCookieName JSESSIONID
< /Location >

When the WebLogic managed server receives the request, the request is load balanced across all the cluster members.