  Quantum computing is changing the way we think about computing. Significant
strides in research and development for managing and harnessing the power of
quantum systems has been made in recent years, demonstrating the potential for
transformative quantum technology. Quantum phenomena like superposition,
entanglement, and interference can be exploited to solve issues that are
difficult for traditional computers. IBM's first public access to true quantum
computers through the cloud, as well as Google's demonstration of quantum
supremacy, are among the accomplishments. Besides, a slew of other commercial,
government, and academic projects are in the works to create next-generation
hardware, a software stack to support the hardware ecosystem, and viable
quantum algorithms. This chapter covers various quantum computing architectures
including many hardware technologies that are being investigated. We also
discuss a variety of challenges, including numerous errors/noise that plague
the quantum computers. An overview of literature investigating noise-resilience
approaches is also presented.
