In the good old days, web content management (WCM) technology primarily served to deliver content to a website-hence the name. At best, multichannel referred to the ability to deliver content to more than one type of website (e.g., an intranet and a public-facing website) or, the ability to repurpose experiences using a simplified template to make it palatable on mobile devices. Multichannel means a lot more now.
Source: Digital Marketing