When to use Accessors in Selenium?

Accessors are mostly used for storing the value in a variable.
The variable can be used for following reasons:
1) To get the value from an element and comparing with some dynamic value
2) To take a logical decision to execute the test steps
ex: if the value of the variable true execute step1 and step2 else step3 and step4
3) To execute some statements in a loop based on the value returned by the element