Quantum computing is a multidisciplinary field comprising aspects of computer science, physics, and mathematics that utilizes quantum mechanics to solve complex problems faster than on classical computers. The field of quantum computing includes hardware research and application development. Quantum computers are able to solve certain types of problems faster than classical computers by taking advantage of quantum mechanical effects, such as superposition and quantum interference. Some applications where quantum computers can provide such a speed boost include machine learning (ML), optimization, and simulation of physical systems. Eventual use cases could be portfolio optimization in finance or the simulation of chemical systems, solving problems that are currently impossible for even the most powerful supercomputers on the market. Quantum computing is a computational method based on quantum mechanics and quantum physics. It is a beautiful combination of physics, mathematics, computer science and information theory. By controlling the behavior of small physical particles such as atoms, electrons, photons, and other microscopic particles, they have achieved exponentially greater energy efficiency, lower power consumption, and extremely faster than traditional computers. Quantum computers can measure multiple phenomena simultaneously through quantum entanglement. DNA computing is an emerging branch of computing that utilizes DNA and molecular biology hardware instead of traditional electronic computing. It involves executing molecular reaction techniques on DNA molecules, which provide high computation power and storage capacity. The main challenge in implementing DNA computing is conducting wet lab experiments in a controlled manner. DNA computing has the potential to integrate with quantum computing and nanotechnology, expanding the scope of research in this field. DNA computing or biocomputing or biological computing is performs calculations with biological molecules instead of traditional silicon chips. The idea that single molecules or even atoms can be used for calculations dates back to 1959, when the American physicist Richard Feynman presented his ideas on nanotechnology. The characteristics of the DNA molecule aid in the induction of quantum features such as superposition, tunneling, coherence, and entanglement. Superposition is the set of quantum particle states in which a particle can be in either a single or mixed state. Quantum computing is based on quantum bits, sometimes known as “qubits,” which may represent either |0> or |1> and the fact that qubits may acquire a mixed state, is known as superposition, in which they can be both |1> and |0> at the same time is fascinating. Consider the following scenario: it’s a coin. When a coin is tossed over the head, it begins to revolve at random. Because it spins randomly, there is a chance of being head, tail, or both at the same moment throughout the rotation. Tunneling occurs when a particle can pass through a potential energy barrier that is typically stronger than the particle’s kinetic energy. In the quantum universe, a particle can pass through a barrier if it does not have any kinetic energy. In the actual world, for example, a ball with 100 J energy may readily overcome a barrier (hill) with just 70 J energy. However, if the ball’s energy is 100 J and the barrier’s energy is 200 J, the ball will never pass through the barrier. The ball will go up to a distance of 100 J before returning. However, in the quantum realm, a particle with less energy than the barrier can also permeate it, which is a fascinating concept. Quantum coherence refers to the concept of superpositioning, which is central to quantum physics and quantum computing. Quantum coherence considers a scenario in which an object’s wave property is divided into two and the two waves coherently interfere with one another. The theory behind quantum coherence is that all things exhibit wave-like qualities. It’s related to quantum entanglement in that it includes the sharing states of two quantum particles rather than two quantum waves of a single particle. Entanglement is a term used to describe a relationship between two or more particles that interact in such a manner that it is difficult to characterize each particle separately. Measurements of the particles, on the other hand, show correlations, therefore the particles must always be characterized as a quantum state of the entire system. Nuclear Magnetic Resonance (NMR) is a physical phenomenon in which electromagnetic radiation is absorbed and emitted by the nucleus in a magnetic field. NMR uses Radio Frequency (RF) to produce a strong magnetic field that excites the nuclei of molecules, causing them to exist in superposition. The superposition principle underpins both quantum coherence and quantum entanglement. In NMR, coherence is a physical condition in which numerous spins line up and revolve at the same speed around the magnetic field direction. NMR relaxation is the reversal of the NMR process. To get the original molecule, NMR relaxation qubits are set in the ground state. In this situation, generating EMR must be halted, and the molecules must then lose energy in order to reach their ground state configuration. This procedure is carried out at two temperatures: room temperature and zero kelvin and is called Reverse Nuclear Magnetic Resonance (RNMR). NMR and RNMR may help to convert a DNA sequence to qubits and qubits to a DNA sequence, respectively. Part I contains the block diagram, architecture, and applications of memory devices such as Random-Access Memory (RAM), Read-Only Memory (ROM), and Programmable Read-Only Memory (PROM), cache memory in quantum, DNA, quantum-DNA and DNA-quantum computing. In Part II, programmable logic devices such as Programmable Logic Array (PLA), Field Programmable Gate Array (FPGA), and Complex Programmable Logic Device (CPLD) in quantum, DNA, quantum-DNA and DNA-quantum computing are described with their architectures and applications. Quantum, DNA, quantum-DNA and DNA-quantum nanoprocessors are designed in the last part which is Part III. Part IV discusses the heat calculation, heat transfer, speed calculation, and data management issues in quantum biocomputing. The computing in quantum biology means the combination of the quantum computing and the DNA computing. Computing in quantum biology is completely new thing that is going to be introduced here in this book.