Metadata is a term we see and hear a lot nowadays. For anyone familiar with Greek or Latin, its meaning might not be obvious – since in those languages, ‘meta’ is about change and position respectively.
But the ‘meta’ in metadata is the modern, self-referential kind – metadata is data about data. It’s data that describes itself, or at least the object or packet it belongs to.
This guide will examine what metadata is and what it’s used for – including implications for your privacy.
Metadata began in the library
In a nutshell, metadata is used to organize information so it’s easier to discover and use.
It began in libraries, as a means of cataloguing archived information. Yes: the famous Dewey Decimal System is an early example of metadata.
Library catalog cards would include systematized data about each book, such as:
- The book’s title
- Its author
- The subject category
- A brief synopsis
- A catalog code that told library users how to find the book’s location
The idea behind metadata hasn’t really changed since this system was created. It’s just gone digital, and is now used for everything from organizing your movie library to directing internet traffic.
You’re generating metadata right now
Now you know what metadata can do, it’s pretty easy to imagine how it can be used to organize all kinds of digital information. And it really is used in a massive variety of ways. Here are some examples of how metadata is used by services you probably use every day.
Email – Every email you send and receive includes the sender and recipient’s name and email address, the time it was sent, the IP address it was sent from, and other message-specific data like the subject line. The metadata is used to send the message to the right place and then organize and display it correctly.
Phone – Telephone networks use metadata to connect phone calls and to log call data for billing and other purposes. Metadata might include the caller’s number, the time and duration of the call, and even the GPS location of the people talking.
Social networking – Have you noticed how third-party apps you sign you up for via Facebook or Twitter always request access to your basic information, friend list and more? What they’re doing is accessing the metadata stored by your social networking account to identify you. Your Facebook likes and interests can also be considered as personal metadata about you, which is used by the service to target ads and page suggestions that might interest you.
Web pages – Metadata is pretty much what makes the Web searchable. Typical web page metadata includes the page title, a description, date published, keywords and much, much more. This metadata is used by search engines to catalog the web, so you can search it easily.
Digital media libraries – Whether you use iTunes or you have a home media server, it’s metadata that keeps all your music and movies organized and nicely displayed. Typical mp3 metadata includes the artist’s name, song title, album name, year of release and more.
Metadata is used in countless other everyday services too – from taking a photo, to watching cable TV.
Metadata also makes the internet work
One other very important use of metadata is in directing and handling internet traffic. Without this metadata, none of the information we transmit over the internet would get where it’s going.
As you probably know, data sent over the internet is chopped up into manageable ‘packets.’ Each of these packets needs to carry information about its destination, where it came from, and how it should be used. And, you guessed it – every packet sent over the internet carries metadata to get that job done.
Metadata and your privacy
By now it should be clear that metadata is really, really useful. But there’s something else about metadata that we all need to be aware of.
Most of the metadata examples above – email, phone calls, social networking and general web browsing – carry personal information about you. And your personal metadata is transmitted over the internet and other networks, where third parties can access it.
People who might access your metadata include:
Hackers – Malicious third parties accessing your unsecured data can use it to monitor your activity and steal from you.
Government agencies – When agencies like the NSA monitor your activities, its legally obtained metadata they use to do it.
Marketers – Services like Facebook store a mammoth amount of personal metadata about you. And since Facebook’s chief source of income is advertising, it’s pretty obvious why.
Be aware of metadata and stay secure
Metadata is everywhere, and in many ways it makes our lives easier and better. But it’s worth remembering that on the internet and other public networks, personal metadata can be seen and used in ways you might not know about.
Whenever you use digital services, you’re generating metadata about yourself. VPN security can help keep your data safe from third parties. But with the ubiquitous nature of metadata today, it’s something we all need to stay aware of.
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