A Central Site is a website where you can place a piece of content and have it displayed on several sites. This is the first thing you need to set up before you can use the Syndicated Content curly bracket.
In an automotive industry, usually, the same information for one model car is used for all its dealerships. By using a Syndicated Content curly bracket, you can get page contents from a central site and display them to multiple dealership sites without having to recreate the content on each site—just put it on a central site, and all pages using that syndicated content gets updated. We talk more about the Syndicated Content here.