An understanding of the extent and intensity of soil erosion is crucial for maintaining ecosystem services, safeguarding biodiversity, and ensuring food security in light of world's population, that is predicted to reach above 10 billion people by the year 2050 and the reduction in arable land. The uppermost topsoil is lost due to soil erosion lowering the agricultural output and raising the requirement for fertilizers, both of which over time can deteriorate over soil health. Additionally, it increases the risk of flooding and degrades water quality by causing sedimentation in rivers and reservoirs. The assessment of soil erosion helps identifying vulnerable regions and informs the advancement of targeted conservation strategies to further prevent degradation. This chapter synthesizes the current understanding of surface soil erosion, focusing on the processes, factors, impacts of erosion, as well as assessment techniques, highlighting their strengths, weaknesses, and areas for improvement. Key drivers of soil erosion include amount of rainfall, land usage practices, vegetative cover as well as topography. Various assessment techniques, such as empirical models (e.g., USLE), remote sensing, and GIS-based approaches, are discussed for their effectiveness in measuring and predicting erosion. Advances in technology have improved the precision of erosion assessments, but challenges remain in addressing spatial and temporal variability.