This particular information is referencing spells that often contain moving parts, whether it be the character, target, or visual effects. More information on the application of Trajectories can be found [here](Link Here).
Example: data "Trajectories" "3d34f1ca-7e7e-4ee7-ad2b-704079f4a19f"
The GUID in the information refers to a Root Template entry, which will dictate both the path of the spell and in some cases, the visual effects as well.