Philotomy Jurament
First Post
I guess I'd go for a combination of the two. I don't consider the setting, alone, a campaign. And I also don't consider a linked series of adventures for a given group of adventurers a campaign. To me, a campaign is a period of time in a campaign setting during which one or more groups of PCs interact with the world and possibly with one another. So you might have multiple groups that aren't necessarily linked, directly, but are acting in the same setting and within the same period of time et cetera. I guess I consider PC interaction with the setting over a given period of time a campaign. Different PCs within that same setting/time period is the same campaign. Same setting two generations later would probably be considered a different campaign. (This also makes me think of Gygax's all-caps admonition about the importance of tracking time if you want to have a meaningful campaign.)
If you have a series of linked adventures with the setting more of a backdrop than as an interactive and integral part of the game, then things like tracking time and resources in the setting are less important, and you have something more like what I think of as an "adventure path." That's not a qualitative label: I don't necessarily think an adventure path is "lesser" than a campaign, although I think everyone has their preferences.
If you have a series of linked adventures with the setting more of a backdrop than as an interactive and integral part of the game, then things like tracking time and resources in the setting are less important, and you have something more like what I think of as an "adventure path." That's not a qualitative label: I don't necessarily think an adventure path is "lesser" than a campaign, although I think everyone has their preferences.