Questions on IPTC information

Hello,

Up to now, I have been using Canon Zoombrowser (ver. 3). I often use the
"photo title" in order so save some information on the pictures. Newer
versions of the Zoombrowser don't show this information completely anymore
and I have no confidence in its database that is not "standard". (And that
had some tendency to ... crash ; version 3 is better now)

Now, after some experimentation with picasa2, I discovered IPTC. Is this
really a standard ?
In any case, the caption information is not stored IN the picture data
itself, so there is still a kind of database, which should be backed-up.

I am very surprised to see that an other program, Irfanview sees the IPTC
information I have made with picasa2.
Is there some system setting that refers to the location of IPTC information
(which, in my case is in some Picasa called directory in documents and
settings) ?

Would you advice me to start using IPTC ?

And if yes, is there any tool to convert the old Zoombrowser data into IPTC
?

Thank you
R-ton