In psychology, central route processing is a method of persuading other people. It’s also known as central route to persuasion, which might make more sense. In this method, a user is supposed to focus on the facts and content of a message when trying to persuade a listener. This is instead of relying on external-to-the-argument factors like the listener’s appearance or personality, etc.
Central route processing is more effective when the audience is engaged, motivated to listen, and the facts are strong and well understood. It’s a useful method of persuasion as it doesn’t involve lying or manipulating an audience, and often has a good long-term understanding of the message if presented well.
If you think of advertisements, many will often only talk about the lifestyle benefits of a product and not list their problems (unless forced to by regulators). This isn’t central route processing, but more of dirty marketers trying to influence unsuspecting people. But when advertisements mainly use statistics and real information to present an idea to an audience, this is using the central route to persuasion.