Highly promising for usage in electronics and optoelectronics, two-dimensional (2D) materials have emerged as an alternative class of nanomaterials with outstanding electrical, optical, mechanical, and thermal traits. The special atomic-scale thickness and high surface-to-volume ratio of 2D materials provide astounding carrier mobility, tuned band gaps, and quantum confinement phenomena. Their basic characteristics—including structural, electrical, optical, and mechanical ones—are thoroughly looked into in this chapter. The subject matter additionally addresses the part 2D materials play in field-effect transistors (FETs), memory devices, logic circuits, photodetectors, light-emitting devices, and solar cells. Future scope of the study has also been discussed along with issues of scalability, environmental stability, and integration with traditional semiconductor technology. Offering unprecedented opportunities for high-speed, energy-efficient, and miniaturized electronic systems, 2D materials are set to transform nanoelectronics and photonic technologies as fabrication technologies and device engineering evolve.