Colloid science is the study of colloids, which are mixtures where tiny particles are dispersed throughout a continuous medium. These particles, typically ranging from 1 nanometer to 1 micrometer in size, do not settle out and can remain suspended for long periods. Common examples of colloids include milk, fog, and paint. Colloids can be classified into different types based on their properties, such as sols, gels, and emulsions. Understanding colloid science is essential in various fields, including food technology, pharmaceuticals, and materials science, as it helps in the formulation and stabilization of products.