It's reasonably common to provide a similar but distinct set of resources based on which environment your stack is running in. In your development environment, for example, you may not wish to create an entire fleet of database servers, instead opting for just a single database server. You can achieve this by using conditionals, such as the following ones:

• Fn::And
  
• Fn::Equals
  
• Fn::If
• Fn::Not
  
• Fn::Or