Nowadays, all companies have separate departments for various things—accounting, marketing, sales, HR, administration etc. Within these departments as well, there is a division of labour. A marketing department may consist of people engaged in different tasks like branding, content-writing, video production etc. Even when internet marketing is outsourced to an agency, it’s possible to hire someone just to do something specific rather than coming up with an integrated solution.
However, it’s a good idea to keep in mind that these distinctions between various marketing tasks aren’t necessary. In fact, they may not always be a good idea. If you hire one person to do your content writing and another to do your branding, there’s going to be a clash between the two. You’re not presenting your customer with a unified company image and your marketing strategy can appear disjointed.