As carbon-based nanomaterials have such remarkable physical, chemical, and electrical capabilities, they have become a major focus of materials science study. A thorough examination of several carbon nanomaterial varieties, such as carbon nanotubes, graphene, fullerenes, and carbon nanodiamonds, is given in this review work. These materials all have distinctive qualities that qualify them for particular uses. This work starts by examining the synthesis processes of these nanomaterials, outlining the ways by which they are made and the variables affecting their ultimate characteristics. The specific features of each kind of carbon nanomaterial will then be briefly discussed in this study, along with their size, structure, and special physical and chemical properties. These materials have a wide range of possible uses in several fields. They are employed in the electronics industry to fabricate sensors, high-speed transistors, and other devices. Their high surface area and electrical conductivity make them useful in energy storage devices like supercapacitors and batteries. They are applied to environmental remediation and water purification in environmental science. They are employed in biomedicine for biosensing, bioimaging, and medication delivery. Notwithstanding the encouraging uses, the large-scale synthesis and functionalization of carbon nanomaterials present several difficulties. This review discusses the importance of carbon nanomaterials by studying their multifaceted properties and potential applications in industries. The novelty of this work lies in its detailed examination of the degradation and toxicity of these materials, which is essential for their safe integration into various technological and biomedical applications. By thoroughly analysing recent experimental results, this review aims to bridge the gap between fundamental research and practical applications.