I am traveling Korea soon. Is there any electronic product or item i have to prepare for my travel?
Look to see what kind of adapter you need to charge electronic devices
Yes. You definitely need a portable wifi device. Free public wifi will be provided only in certain places, such as coffe shops. or hotel etc. To resolve such inconveniences, you need to rent a portable wifi device at the airport. What I can think of is Olleh and Widemobile. Widemobile is little bit cheaper(4500KRW/day) than Olleh.
Just got back from 2 weeks primarily in Seoul and Daegu. In South Korea the power sockets are type C and F. This is what I used: https://www.amazon.com/gp/product/B008JCVF0U/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1
I have US T-Mobile service and my included data plan worked everywhere.
Additionally, I had no trouble with any of my credit cards but finding ATMs that accepted my debit card was problematic.
One more bit of technology to pre-install if you plan to use taxis: the WAZE navigation app. You can search for the destination you want in English and it will show the destination in both English and Korean. Since Korean taxi drivers universally use WAZE, just hand them your phone, they'll read the Korean, then hand back your phone and get on the way.
Enjoy your trip!
I wanna add that you can purchase those adapters /converters from B type to C type at the airport for a like 1000 won if I remember correctly.