Question

is South Korea is well developed country
define some bad and good culture of there

Answer 1

South Korea's growth is a combination of quick achievement of 100% literacy that started in Japanese occupation, significant land reforms that created the middle class, significant market reforms that helped the middle class trade with the world and a demographic one-time lottery. Most communist nations miss the stage 3 thus they are educated with land reforms with stunted growth. Many crony capitalist nations miss stages 1 & 2, thus they have a "free" market but without a populace that is educated and with land to make use of the market. South Korea ticked off all its boxes.

The culture of korea is a good one though.

1)Their traditional dress is Hanbok

2)Traditional food- Kimchi

3)Have to call all the people with respect