In general, Eau de Cologne basically means it is a lower strength fragrance, meaning that around 90% of what's actually in the bottle is just alcohol. Eau de Toilette is stronger, and Eau de Parfum is the strongest. Terre D'Hermes is an example of perfume that come in both Eau de Toilette and Eau de Parfum strengths.
If you look at the bottle or the box of whatever you own, you'll probably find the words "Eau de Toilette" on there somewhere, meaning it's an EdT. Or maybe even Eau de Parfum. Creeds and Bonds are generally EdP.
The ultimate example of a modern cologne is Mugler Cologne. I believe that Gianfranco Ferre Bergamotto Marino is also an EdC.