Particle size classification system is a method used to categorize soil particles based on their size distribution. It is an important aspect of soil science and engineering as it provides valuable information about the physical properties and behavior of soils. However, it does not directly signify soil types.

Particle size classification system mainly deals with the size distribution of soil particles and categorizes them into different groups based on their sizes. The most commonly used classification system is the Unified Soil Classification System (USCS), which classifies soil particles into several groups such as gravel, sand, silt, and clay.

Soil types, on the other hand, are categorized based on various factors other than particle size, such as mineral composition, organic content, and degree of weathering. Soil types can include categories such as loam, clayey soil, sandy soil, peat soil, etc.

Although particle size is an important factor in determining soil properties, it does not provide a complete picture of the soil type. Different soil types can have similar particle size distributions, but they may differ significantly in other properties such as permeability, compressibility, and shear strength.

Particle size classification is useful in engineering applications such as soil compaction, filtration, and drainage, as it helps in selecting suitable materials for construction purposes. It also provides a basis for understanding the behavior of soils under different loading and environmental conditions.

In conclusion, while particle size classification system is an important tool in soil science and engineering, it does not directly signify soil types. Soil types are determined by a combination of factors including particle size, mineral composition, organic content, and weathering.