New To E-Currency

I saw all the posts about the apparent demise of E-Gold and it sparked my interest in learning a bit more about e-currencies.

I guess I'm missing something, because I don't understand the difference between say v-money and GoldEx. What specific service does v-money provide and how does that differ from the services offered by GoldEx, which is apparently an exchanger of some type. How might I use these services?

Furthermore, I'm confused because many of the web sites refer to e-gold and I'm unclear as to whether they are speaking about the brand or e-currency in general.

Thanks from the newbie.