What Commerce is

In general it means to conduct transactions online. It is considered a technological term because any kind of commerce conducted online requires a technological application behind it. From a marketing point-of-view, commerce is discussed with reference to the three big C's: content, commerce, and community. These are thought to be the three components driving the new economy.

The meaning of Legacy business

Slang for a traditional brick-and-mortar firm. Accurate or not, anything characterized as "legacy" is perceived to be old or outdated (as opposed to a new economy company, for example).