Is it marketing or is it sales?

We tend to try to label everything. In business marketing and sales are frequently artificially separated. In reality, it's all about moving future customers to current customers. Awareness and demand creating activities typically are categorized as marketing while matching specific prospects to specific products or services is called sales.
Regardless of the titles and the segregation of activities, your business growth needs to focus on the seamless process of identifying potential customers, packaging your product/service offering to exceed their expectations, confirming your working relationship (closing), and maintaining their business (nurture). Whether you call it marketing or sales, the three basics steps to business growth are 1) target your audience, 2) value proposition, and 3) customer service.