Reference: Architecture diagrams

Basic architecture diagram (single level)
A simple diagram of the simplest setup commonly seen in a production environment. Two servers - one web and one database.

Simplified architecture diagram
A common architecture with databases removed for clarity. Staging and Development may share a database server. Generally, Production should have a completely separate database server.

Content flow detail
A content author creates content in staging, which is stored in the staging database. On site sync, data is pulled from the database and transferred to the production server, which in turn stores the content in the production database.

Code flow deployment strategy

Simple production infrastructure diagram with hardware load balancer
Common on premise simplified setup.

Simple production infrastructure diagram with software load balancer
Common in on premise or in cloud. Suitable for both AWS and Azure.

Simple production infrastructure diagram with Azure
When using Sitefinity CMS on Azure Cloud Services in a load-balanced scenario you do not need to configure Sitefinity CMS for load balancing.

Production geographic distribution diagram
Geographic area should have its own database for reasons of latency.