Multichannel marketing focuses on getting a user from point X to point Y by sending a common message with the help of individual channels. For instance, you might advertise a certain promo code on your website, social media platform and email newsletter with the intention of getting the target audience to use the code to purchase your offerings or at least engage with them.
https://sinch.com/in/blog/know-difference-between-multichannel-and-omnichannel-marketing/