With the advent of quantum computers classical and currently deployed cryptographic systems do not guarantee data security anymore. More critical, malicious agents can already today store data to be later decrypted when practical quantum computers become available. Quantum communication uses quantum bits (or qubits) instead of classical bits for the transmission of information. The use of photons as qubits opens practical possibilities for the development of unconditioned secure crypto-key transmission in the form of quantum key distribution (QKD). The course introduces the fundamentals of quantum communications. Although we survey different functions of quantum communication, we focus on quantum cryptography and specifically on quantum key distribution (QKD) because of its maturity. We learn about the main QKD protocols, learn by doing practical experimental measure- ments. We learn how to integrate QKD with classical optical fibre networks and on the roadmap to build a QKD network. Finally, we learn about emerging use cases and remaining technological chal- lenges for mass deployment. At TU/e, the newly created EHCI (Eindhoven Hendrik Casimir Institute) supports the setup of a Quantum Technology master track in Applied Physics which brings together courses not only from AP but also from the Department of Electrical Engineering and the Department of Mathematics and Computer Science. Within this context and given that TU/e does not yet have a course on quantum communications, this proposal is set up as such a course.