As you develop your skillset in PLC programming, you'll realize that there are many ways to accomplish the same task. However, certain approaches would be much more applicable in certain cases and less so in others. Through ladder logic, you can create programs that are easy to maintain, understand and augment over-time. That being said, most PLCs, including Allen Bradley ones, offer others ways of implementing logic. These different ways of programming are as follows: Structured Text [ST], Function Block Diagrams [FBD] and Sequential Function Charts [SFC].
This is a companion discussion topic for the original entry at https://www.solisplc.com/tutorials/introduction-to-structured-text-programming-in-rslogix-and-studio-5000-allen-bradley