Soil strength refers to the ability of soil to support loads without collapsing or deforming. It is influenced by factors such as soil type, moisture content, and compaction. Stronger soils can bear heavier structures, while weaker soils may require reinforcement or special construction techniques. There are two main types of soil strength: cohesion and friction. Cohesion is the attraction between soil particles, while friction is the resistance to sliding between particles. Engineers assess soil strength to ensure the stability of buildings, roads, and other structures, making it a crucial aspect of geotechnical engineering.