元數據是一些資訊，用於排序、組織甚至使查找其他資訊更容易。簡而言之，元數據是關於數據的數據。元數據的一個示例是圖書館目錄卡中的內容。這些卡片包含有關書籍的一些數據。例如，卡片可以有一個類別、一個代碼、一個書名、它的作者和書的簡要簡介。使用此卡片，您可以在圖書館中找到書籍的確切位置。但首先，必須有一種方法可以首先出現元數據。
元數據、互聯網和數字服務
In this digital era, the internet and many digital services rely on metadata for them to function properly. For instance, the internet uses packets which carry information from one destination to another. the packets contain a header which is full of metadata. This metadata informs the internet services and nodes where the respective information should be directed. Below are some ways in which metadata makes other digital services we use daily to work as intended;
上網 – 如果不是為了元數據，我們將找不到我們在互聯網上搜索的網頁。網頁帶有一些強制性的元數據，包括其標題，一些描述，關鍵字等。搜尋引擎使用此元數據來獲取網頁。
Social media and networking – our social media accounts almost have every detail of information about us. if you have been keen, you might have realized you have used Facebook, Twitter or Google to log into other third-party apps/sites. Usually, when this happens, you give access to basic information such as date of birth, your friend list and even permission to post on your behalf. In simple terms, these third-party apps are requesting access to your metadata in which they use to identify you when you log in in future.
Digital entertainment catalogues – have you ever wondered how after listening to a few songs in online streaming services, you get suggestions that match your preference? Or after watching some few movies in Netflix you get a new row of movies you might like? it’s all because of the metadata sometimes scrapped from items you had selected earlier.
通常，我們以數位方式使用的所有內容都有元數據，從音樂到電子郵件，甚至電話。
元數據和您的隱私
As much as metadata is useful, it’s also a threat to your privacy. As seen above, most metadata contain our personal information such as what third-parties request off social media sites. Also, cookies and other trackers are constantly collecting metadata and sending them to data-hungry startups which in turn have neatly compiled our preferences and browsing behaviours. This metadata becomes harmful when it is sold to other third parties, that’s when privacy risks and threats arise. Below are some entities that can compromise our privacy by having access to our metadata;
網路犯罪分子
cybercriminals can have access to our metadata from a third-party organization and even from cookies and trackers. With this metadata, they can propagate further attacks such as blackmail, vishing, and smishing attacks and to some extent identity fraud.
政府機構和機構
Intelligence agencies may gather metadata from ISPs and other organization which they then use to monitor an individual.
行銷
Most organizations use ads as their main source of income. This can be done directly and indirectly. For instance, you might have noticed you are getting a lot of ads on your social media sites. Most of the ads are not social media related but they are about a product and chances are 80% you might be interested in the product. All this is possible via metadata. For instance, your Facebook interest and likes can be used to suggests pages and target you with ads.
如何保持安全，使用 VPN
由於元數據運行在數位世界中，因此很難避免共用您的資訊，您現在甚至可能正在生成更多元數據。您唯一能做的就是將風險降至最低，這可以通過使用 VPN 來實現。
