What happens when put a Finder alias in a Dropbox folder? I have several folders and files that I would like to link to a local folder that happens to be a Dropbox folder. Specifically I'd like to put Finder aliases to some files and some folders into a folder that is on Dropbox. What happens when I do this? What is synced to Dropbox? Is it just the Finder alias itself (a special kind of file only meaningful on macOS) or are the linked-to files or folders copied to Dropbox?
The Finder alias will appear as a zero-byte file in Dropbox. Any files linked to it will not be uploaded.

If you would like to have Dropbox sync the contents of the alias, you can instead use what's called a symbolic link. Basically, it's an alias that the operating system (and Dropbox) treat as indistinguishable from the actual folder. This question on SuperUser answers how to create a symbolic link.