Quantum computingQuantum computing is promising to solve certain classes of problems more efficiently than classical computersClassical computer by leveraging the principles of quantum mechanics. As quantum hardware continues to evolve, it is important to view these systems from a computer architectureComputer architecture perspective. For example, it is necessary to examine how qubits are arranged, controlled, and interconnected to form gates and circuits. Similarly, we need to explore how data and entanglementEntanglement are routed within and between quantum processors. This chapter provides an overview of the architectural structure of quantum processing unitsQuantum Processing Unit (QPU), including both single-core and modular multi-core configurations. It also explores how communication is managed in quantum computingQuantum computing systems, introducing the concept of quantum on-chip networksNetwork on Chip. Finally, we discuss quantum computingQuantum computing simulators that are essential tools for exploring quantum computerQuantum computer architecturesComputer architecture.