Here are some commonly under-defined and confused terms which are sometimes even used interchangeably (erroneously). Each are different and have their own technologies and roles in a company.
A very broad term which means a particle which is distributed, or displayed about your company or product. It is anything which goes out into the public, and exposes them to your brand, by whatever means (paid, free).
Examples: press releases, flyers, billboards, posters, a news event/story, viral social media post, free pens with your logo on them, etc etc
An advertisement is a piece of paid promotion. It is displayed to the public. Some ads directly try to sell, other try to create mystery and ‘buzz’, others just try to build awareness.
For an advertisement or any piece of promotion to function or get any results at all it must have been created with the principles of marketing.
Native advertising are ads which don’t look like ads. Articles, posts, videos which seem like normal content, however they were crafted by marketers and then paid for by the company to be featured on a website.
A very broad term used to describe the processes or techniques/methods of making a product sell-able, making it wanted by the public. In earlier days all one had to do was make a simple advertisement without any afterthought. Now, with the markets overcrowded with competitors it is necessary to convince consumers to buy your product.
Marketing uses such things as:
-surveying & research
Additionally there is Content Marketing, which is essentially the creation of highly valuable free content which then creates a positive experience in the consumer (since its free and great) and makes them more likely to become interested in your brand and buy from you.
Public Relations or PR could be considered the marketing of people, ideas or companies (making them sell-able). Whereas marketing could be considered to be for products. This is a little loose so let’s be more specific.
The purpose of PR is to change how people feel about something: change their opinion, strengthen their opinion. A company’s PR would be how the public feel and think about them. PR doesn’t typically try to sell a product. It tries to sell ideas, or enhance the image of something. PR is very often associated with volunteer work, charity, social betterment activities, donations etc.
A company will use PR to make itself more human, and create a culture within the company with which the public can relate and support, thereby enhancing their image.