In the communications industry there are SOME fairly bright definitions:
- Advertising and marketing are when an entity pays some other entity to transmit content
- Public relations is when an entity, without paying, causes another entity to transmit content
- Public affairs is when an entity causes a governmental entity to consume specific content at minimum, up to possibly influencing decisions. It should go without saying that this is without paying as well, otherwise it's corruption/bribery
...an entity A pays some other entity B to transmit some specific content to a third party to induce the third party to take action that benefits the paying entity A.
- Advertising and marketing are when an entity pays some other entity to transmit content
- Public relations is when an entity, without paying, causes another entity to transmit content
- Public affairs is when an entity causes a governmental entity to consume specific content at minimum, up to possibly influencing decisions. It should go without saying that this is without paying as well, otherwise it's corruption/bribery