What are the differences between propoganda and advertising campaigns?

In the old days, Propaganda was a term that came from religion-- specifically Catholicism. It meant "to spread the faith," especially by missionary work. Later, the Word took on the meaning of intentionally spreading information that was manipulative, used by a government or by the powerful, to influence public opinion and persuade people to do what those in power wanted. Advertising can certainly be a kind of propaganda, but historically, the main purpose of advertising has been to support consumerism-- companies use advertising to persuade people to buy certain products or shop in certain stores.

These days, in this era of social media and 24/7 cable TV, politicians have embraced advertising to get their messages out and try to demonize their opponents-- whether to persuade people to vote for them, or to scare them into supporting certain policies. As the other comment on this page notes, political propaganda (such as so-called "attack ads") frequently relies on half-truths, lies, exaggerations, and scary claims. So, the difference between the two in modern times is that advertising does not have to be propaganda, and it does not have to have a malevolent purpose-- it can simply be a way to persuade potential customers to spend money. But there is definitely a place where advertising and propaganda align-- in political campaigning.