SSL or TLS?

I am using a newsprovider that accepts SSL on port 563,
I use all this with the Opera browser which in the
settings for news has a TLS box that needs to be
checked.

I have been searching information about the difference
between SSL and TLS, and all I understood is that TLS
is some SSL version 3, the latest. But I still do not
understand what is exactly the difference, my newsprovider
names it SSL, my newsreader TLS but it works as if it
was the same thing, yet itsn't otherwise they wouldnt
have a different name.

Anyone can clarify or give some link that explain how TLS
is different from SSL, and how does it affect the average
user?

I have also seen this difference many times in email
services that promise SSL connexions and others name it
TLS.