What does it mean by Load Balancing

Load Balancing is an associations between real servers and virtual servers. The real servers are your application servers. The virtual servers have one or more Virtual IP addresses.  The real server can be associated with virtual server by binding TCP ports with that of port on virtual server.

Load Balancing maps one virtual server connection to multiple physical servers, Allowing single IP address can serve as the connection point for multiple TCP services . These services can be located on a single server or multiple servers.