Carbon nanotubes (CNTs) are one of the most distinctive innovations in the world of nanotechnology. CNTs have been intensively examined by numerous experts across the world over the last two decades due to their enormous potential in a variety of technical fields such as nanoelectronics, biotechnology, material science, polymer, composite, and textile industries because of their excellent polycrystalline, electrical, mechanical, and thermal characteristics. CNT synthesis may be accomplished using a variety of approaches, for example, the arc-discharge process, chemical vaporization deposition (CVD), and laser ablation. There are three types of CNT walls: single, double, and multi-walled. The current study focuses on the synthesis, functionalization, characteristics, and applications of carbon nanotubes (CNTs).