what is a target object in spring AOP

I am beginner to spring aop and i am going through spring aop documentation to understand the concepts but failed to understand 'target object'.

the documentation says target object is the "object being advised by one or more aspects. Also referred to as the advised object".

what is the meaning of being advised by one or more aspects here? can anyone explain me what is target object in Lyman terms as i am still a beginner.

Solution

For a simple explanation of some basic AOP terms please refer to my other answer. Please read that one first before continuing to read here.

So the target object is the (Java or Spring) component to which you want to add new behaviour, usually a cross-cutting concern, i.e. some behaviour that is to be applied to many classes in your code base.

An aspect is a class in which you implement that cross-cutting concern and also determine where and how to apply it. The where is defined by a pointcut, some kind of search expression finding the relevant parts of your code base to apply the behaviour to. The how is implemented in an aspect method called an advice.

So when we say that an aspect advises an object, it means that it adds (cross-cutting) behaviour to it without changing the class itself.

In Spring AOP this is mostly method interception, i.e. doing something before or after a method executes.
In the more powerful AspectJ you can also intercept changes of member variables and constructor execution. Furthermore you can change the class structure itself by adding new members or methods or making the target class implement an interface etc.