It's nice to brag about your business successes. And almost always such stories are listened to attentively by competitors. If you open up at this point, you could accidentally say too much. Therefore, you need a deterrent factor. Such a factor is a special agreement that employees sign to understand what they must not tell anyone, especially competitors. If an employee signs such an agreement, fear of penalty sanctions, most likely, will stop him from excessive frankness. The name of this agreement is the NDA.