Link Building Does Not Equal Content Marketing
Link Building is acquiring links to improve your search rankings. It involves performing keyword research to determine what you want to target, finding sources related to those keywords (or identifying sites that are linking to your competitors), and then doing one-to-one outreach with those sources to obtain a link.
Content Marketing is creating content to move your users through your marketing funnel. It involves creating buyer personas to determine who your buyers are, finding what they currently use to get content, and delivering content in their preferred medium to help them make a purchasing decision.