tl;dr Listicle of five service layouts for different horizontal and vertical scaling. Provides a paragraph about each and pros/cons. Useful if you only have five minutes to learn about the following terms; not, if you've already spent five minutes learning about the following terms.

1 Everything On One Server

2 Separate Database Server

3 Load Balancer (Reverse Proxy)

4 HTTP Accelerator (Caching Reverse Proxy)

5 Master-Slave Database Replication