I encountered this term in Spring framework article as well as here at TSS in the "Test your Aspects" article.
What is the full form and what does it mean?
My dear friend probably what you read was "AOP" not "AOB"(Let me know otherwise)
AOP stands for Aspect Oriented Programming.
Its a programming paradigm like OOP(Object Oriented Programming). Its a way you program by encapsulating/modularizing logic for cross cutting concerns - No, my communication is not that good to explain it within here.
AspectJ is java implementation for this - its enormous fun.