The creation of a quantum computer is one of the overarching challenges of our times. A quantum computer will open before humanity the solution of many fundamental and applied problems. Scientific groups and IT giants have created prototypes of quantum computers. Today, these devices have limited power, which is not enough even to compete with classic computers. However, modern scientific advances are rapidly approaching the moment of creating a universal working prototype of a quantum computer. Such importance of the quantum computer, as well as its rapid development, allows claiming that any scientist needs to understand the principles of operation and the structure of this device. In this course, you will explore in detail the one-way quantum computing model. This model is one of the most promising in terms of practical implementation. In addition, you will understand what continuous-variable quantum computation is and how this type of computation differs from the usual computations with qubits. In addition, you will explore in detail the methods of quantum error correction that can be applied to all models of quantum computation. The authors of the course belong to the theoretical quantum-optical school of St. Petersburg, which arose at the dawn of the formation of this science. We work at St. Petersburg State University and are part of the expert community "Quantum Technologies Consortium" of the state support program for NTI centers, which supported the creation of this course.