Used to store cross-resource accessible information. This functionality stores an object on a player that can than be accessed with getSyncedMeta. This can also be accessed on client-side.
This type of meta is accessible anywhere but can only be set on server-side.
setSyncedMeta(key: string, value: any): void;
You can store literally anything. Except functions.
Real World Example
player.setSyncedMeta('myData', 'hello from meta');