Significant research employing nanomaterials has been conducted in the field of nanotechnology over the past few years. Due to the significant advancements made in a number of industries, including electronics, energy, medical, cosmetics, food engineering, telecommunications, and agriculture, nanotechnology is advancing quickly. As a result, nanomaterials are the foundation of nanotechnology. Due to their small size, nanomaterials have special optical, magnetic, electrical, and physical, reactivity, strength, surface area, sensitivity, and stability features. Surprisingly, the phase change occurs when bulk materials are converted into nanomaterials, which means that materials that were previously non‐magnetic become magnetic at the nanoscale. Because of its unique features, nanoscale matter is a separate form of matter from the solid, liquid, gaseous, and plasma states. Nanomaterials' characteristics are mostly determined by their shapes and sizes. In this paper a critical overview of nanomaterials, their varieties, characteristics, synthesis techniques, and applications in various fields is offered.