This document discusses different WebSphere Application Server topologies: - A stand-alone server topology involves installing WAS on a single machine with one application server and no load balancing or high availability. - A vertical scaling topology uses a cluster of three servers to perform basic load balancing at the web server level. - A horizontal scaling topology creates logical server units across multiple systems that can each handle requests, without requiring an IP sprayer. - A horizontal scaling topology with a load balancer has two active web servers that perform load balancing between application servers through the web server plugin, with the load balancer spraying requests to the web servers. - A reverse proxy topology typically uses proxy servers in a DMZ configuration for added security and