Can you elaborate on what guanxi entails?

Guanxi really just mean "relation". In this context, it means long term business relations alloing for trust and mutual respect, where each part knows that the other part will return favors and keep the relation balanced. It also, as a side-effect, facilitate corruption, but it does not imply it. The Chinese have a long culture of managing social relations, so this side is very developped, but you have the same in higher society in Europe.