UML aggregation vs association -

here am, question aggregation , association. wanted learn basics of uml, started reading "uml distilled" martin fowler. read both chapters classes, , there 1 thing can't grasp think, , aggregation vs association. in book there quote:

in pre-uml days, people rather vague on aggregation , association. whether vague or not, inconsistent else. result, many modelers think aggregation important, although different reasons. uml included aggregation (figure 5.3) hardly semantics. jim rumbaugh says, "think of modeling placebo" [rumbaugh, uml reference].

as understand quote , topics read on stack overflow doesn't matter 1 of 2 relations use, mean bassicly same, or there situation usage of aggregation instead of association justified and/or not change 1 without changing "meaning" of class diagram?

i asking this, beacuse book 2003, , things change during few years.

rumbaugh's statement telling , uncle bob's advice. i've said elsewhere, aggregation semantically weak offer nothing practically beneficial. has 1 valid corner case (acyclicity of recursive relationships) few people know , understand that. end having point out in comments anyway.

i don't use it. , have never felt loss. stick simple binary associations , focus on matters - getting cardinality , naming right. you'll far more trying decide undecidable association vs. aggregation.

hth.