Qubits are such two-level quantum mechanical systems in which the quantum states can be coherently controlled. One of the most successful realizations of qubits is the artificial atom in solids that is called point defect. We show on the exemplary nitrogen-vacancy center in diamond how the readout and initialization processes of this type of qubits work and how they lead to novel technologies with unprecedented sensitivity at the nanoscale which may revolutionize the discoveries in solid state physics, biology, human diagnosis and therapy. Furthermore, they are prospective building blocks for quantum communication and have a great potential in the realization of novel quantum computers. We show that the success of nitrogen-vacancy center in diamond opened up a new research field to seek alternative systems acting as quantum-coherent materials that suit the desired properties of the selected applications and technologies.