My wife is Korean, so I'm exposed to all kinds of interesting culture differences between America and Korea. I'd like to share a few of those culture differences so that people can learn more about Korean culture. I also want to show people that a lot of things we take for granted as just "how things are done" are actually nothing more than cultural norms that can and do vary from place to place.
Amazon identifies every product for sale with a ten-digit alphanumeric code called an ASIN (Amazon Standard Identification Number). Whenever you visit a product page on Amazon, these number is somewhere in the URL; however, it's not always in the same place in the URL. This makes it a little bit hard to pull the ASIN out of an arbitrary URL.
If you use public WiFi, you need a VPN. You can pay to use a commercial solution, or you can set one up in your own home for free. The problem with using public WiFi is that any data you send to an HTTP website is in the clear and available for anyone to read. A VPN encrypts your web traffic from your phone/desktop and sends it to the VPN server. Your traffic then proceeds to its destination encrypted or not based on if you're visiting a website over HTTP or HTTPS. The important part is VPNs make it so that no one sitting in the same cafe as you can snoop on your web traffic. Finally, VPNs can also be used to access location-locked services like Netflix even when you're travelling abroad. When you use a VPN, it's just like you're browsing the web from your home.