Can someone explain to me in laymen terms what proxypass does and on a SLES10SP2 / OES2SP1 server how would it effect iManager?

My iManager was working fine and for an unknown reason now I only get a 404 error. Also Apache will not load unless I comment out line two of my nps-Apache.conf file which is ProxyPass /nps ajp://localhost:9009/nps.

I'm not proficient enough with SLES and Apache on SLES to fulling understand whats going on. Any suggestions?