These are called QR codes, or “quick response” codes, and they’re everywhere. If you’ve spent any time shopping, traveling or socializing these days, you have no doubt seen these black and white dotted squares -- as well as people scanning them with their smartphones.

Consider QR codes a kind of 2-D barcode that has a number of advantages over traditional lined barcodes. They can store a lot more information (more than 7,000 numeric characters vs. 20), they can be scanned quickly from any angle, and they’re designed for consumers and businesses alike.

To scan a QR code, all you need is a smartphone with a camera and software that can interpret what the code means. In some cases, a QR code reader will be preinstalled on your smartphone. If it’s not, there are many free ones to download for your device. Some QR code readers will be built into existing apps too, such as Research in Motion’s BlackBerry Messenger (BBM).

Once a QR code is scanned, it can take you to a website, launch a YouTube video, add a name to your contacts list or download an MP3 to your phone. QR codes are meant to quickly bridge the gap between old and new media. For example, if you enjoyed an article in your local newspaper, you can scan a QR code at the end of the piece. The code may take you to a website that has more information on the subject you just read about.

QR codes can also be used by airlines, which may text you a code that serves as a digital boarding pass. The gate attendant will scan it as you board the plane -- no paper needed. Or what if you’re walking by a restaurant? Scan the QR code in the window and it may open the establishment’s menu, hours of operation and perhaps a video message from the owner.

Are QR codes safe? For the most part, yes. When you scan a QR code, none of your smartphone’s information is recorded by the person behind it; it’s a one-way scan. The person who offers the code likely knows their code has been accessed, so they can track how many people are using the technology, but they don’t know who you are or how to reach you.

But there is a small caveat: If a malicious person wants to distribute malware, such as a virus or spyware, it would be fairly easy to do so via QR codes because consumers don’t really know where that code will take them. It’s usually to a legitimate website or piece of media, but as phones become more prone to malware, the risk of QR codes may be a more legitimate concern in the near future. If you’re worried, just remember to only scan QR codes from trusted sources.