Collusion refers to the bidding unit or bidding unit and the bidding unit collusion with each other to win the bid. This behavior is usually manifested in the negotiation between the bidders to take turns to win the bid, inflate or reduce the bidding price, leaking each other's bidding and other behaviors. If found between the bidders have the above behavior, can be judged as collusion.
Bid-rigging refers to the mutual agreement among several bidders to unanimously raise or lower the bidding price for bidding, limiting the means and behavior of competing bidders, excluding other bidders, so that a certain stakeholder can win the bid, and thus gain benefits. Such behavior usually manifests itself in acts such as negotiating bids and agreeing on actions among bidders. If multiple bidders are found to engage in such behavior among themselves, they can be judged to be bid-rigging.
Bid-rigging and bid-rigging are both violations of the law and are subject to legal sanctions. In the bidding process, the principles of fairness, impartiality and openness should be observed to maintain market order and fair competition.