Water is one of the most vital substances on the planet that supports and sustains life. One of the most crucial challenges of our time is water. It is a basic need for all living beings. Worldwide, a large amount of wastewater is produced daily from home and industrial sources, creating problems such a water shortage and environmental degradation. Water that has already been utilized is called wastewater. It has been observed that the wastewater released varies in composition according to the kind of industry and the municipal sources. Microorganisms, heavy metals, organic pollutants, pesticides, phthalates, polycyclic aromatic hydrocarbons, emerging contaminants, and potentially dangerous wastes are all present in it. Among the most effective methods for removing these contaminants in recent times is the adsorption phenomenon. The presence of various contaminants in wastewater can be efficiently reduced by the simple, efficient, and affordable process of adsorption. Selection of suitable adsorbent is the crucial technique in this operation of adsorption. A versatile adsorbent is activated carbon (AC). Their maximum surface reactivity, large surface area, and microporous form are what give them their adsorptive capabilities. To enable recovery and filter, eliminate, or change the toxic components from gases and liquid solutions, they are used to purify, decolorize, deodorize, dechlorinate, separate, and concentrate. As a result, a variety of industries are interested in AC for the process of adsorption. This review paper briefs the characteristics of AC and their preparation techniques. It discusses the numerous approaches for modifying the surface of AC with significant adsorption capability. It also emphasizes the usage of AC with the elimination of different toxins found in waste water.