Content development is researching, producing, and publishing information to meet a strategic goal. That goal will either be to build a connection with an audience or to encourage some kind of marketing or sales outcome. Content development is therefore a vital part of a content marketing strategy.
Content marketing involves the creation and sharing of online material (videos, blogs, social media posts, etc.) which does not explicitly promote a brand, rather it is intended to stimulate interest in your organization's mission, or your products and/or services. Social media can be an integral part of content marketing.