Hi there,
If i'm not mistaken, i think E-Biz is a subset of E-Commerce.
E-Biz encompasses the buying & selling online, relationships with customers, suppliers, and other online trading partners for a particular online company for instance whereas E-Commerce has a broader perspective.
In essence, E-Commerce looks at the entire online business value chain from the beginning till the process ends. It is the application of information and communication technology between many parties involved and of course, these are carried out electronically.
Hope it helps
cheers,
coRn