Adsorption is a physicochemical process that removes bio-refractory substances such as organic compounds and heavy metals by concentrating the pollutants on the surfaces or interface between two phases. It occurs mainly in four stages: bulk liquid transfer, film diffusion, pore diffusion, and adsorption (surface attachment). The pollutant that gets adsorbed on the surface is called adsorbate, while the solid adsorbing material is the adsorbent. The commonly used adsorbent materials are activated carbon, wood sawdust, Activated alumina, and synthetic polymers and recent advancements include nanoparticles such as carbon composite and nanotubes. The adsorption performance is directly proportional to the surface area of the adsorbent, temperature, solution pH, and other operational conditions. There are three significant types of absorption: physical adsorption (physisorption), chemical adsorption (chemisorption), and ion exchange. Adsorption kinetics and equilibrium are crucial in understanding the adsorption mechanism and how the adsorbent interacts with adsorbate. These Kinetics illustrate the adsorption process's adsorptive capacity mainly described using an isotherm. The standard isotherms include the Langmuir isotherm, Temkin isotherm, BET Isotherm, and Freundlich model. Adsorption can be operated in two modes (batch and continuous) depending on the required reaction kinetics, adsorption capacity, and equilibrium time for pollutant removal.