Synchronicity verses Serendipity?

I love the Grizzwells, they always get it right.  I wrote a blog yesterday about Synchronicity and when I read the paper last evening this was the cartoon.  Now I feel that is just a bit of synchronicity don't you?   But my question now is whats the difference between Synchronicity and Serendipity?  So I looked them up. 
 Wikipedia says:
Serendipity means a "happy accident" or "pleasant surprise"; specifically, the accident of finding something good or useful while not specifically searching for it.

And it also says:

Synchronicity is the experience of two or more events that are apparently causally unrelated or unlikely to occur together by chance, yet are experienced as occurring together in a meaningful manner. The concept of synchronicity was first described in this terminology by Carl Gustav Jung, a Swiss psychologist, in the 1920s.

So I see a similarity here but I think they are actually different.  Would love to hear someone elses opinion on this. So keep looking for these in your life.  They just may be a key to something important you are supposed to be paying attention to.