Quantum mechanics has often been regarded as an abstract theoretical sandbox to describe peculiar effects on small size scales. However this attitude has changed drastically over the past years and nowadays quantum effects are exploited in new applications---applications that would be impossible in a pure classical world. One cornerstone of this new emerging technology is quantum key distribution, that represents a way to allow provable secure communication between spatially separated users. In this talk I'll present the basic idea behind this new type of cryptography scheme and explain the generic security features that it offers. Afterwards I'll mainly focus on current 'practicality' issues of this field. These points are essential in order to turn this beautiful, but rather abstractly proposed idea into an actual security system that is available with present-day technology. These ideas helped quantum key distribution to move out of the lab and to become interesting for companies that are already selling such devices. No background of quantum mechanics is required for this talk.