The difference between marketing and sales is: marketing is everything that you do to reach and persuade prospects and the sales process is everything that you do to close the sale and get a signed agreement or contract. Both are necessities to the success of a business. You cannot do without either process. If you work to strategically combine both efforts you will experience a successful amount of business growth.
A marketers job consists of identifying the customer and finding the best avenues to reach them.  This can include advertising, public relations, social media strategies, events, pretty much anything that you do to attract your customer.      Marketing is typically a media driven endeavor that introduces your company to prospective customers. Whereas sales is usually human driven, with a salesperson introducing your company to prospective customer. While sales and marketing are different processes,  it’s critical for “marketing” activities and “sales” activities to be closely coordinated.  By coordinating the processes brands learn  to speak with one, consistent voice.  They also form a synergy that increases sales and profits.
The fashion industry finds itself driving revenues through the sales process.  Companies hire salespeople to contact buyers with the goal of bringing them into the showroom to see their collection and persuade them to buy the line.  This is a tried and true method.  But, by introducing the use of marketing into the process a brand creates an attraction  that pulls in prospective buyers who then come into a showroom with an intention to buy the line.  Or at the very least a desire to like the line.
Integrating the two processes increases sales efficiency, eliminates wasted marketing dollars, creates effective sales tools, and increases your pipeline of new prospects.  It additionally educates the end consumer to the product which improves store sell throughs.  So while there is definitely a difference between sales and marketing there are major advantages to leveraging the two together.