1. Social stratification refers to the hierarchical arrangement of individuals or groups based on characteristics such as income, education, occupation, and social status. Social differentiation, on the other hand, simply refers to the existence of differences among individuals or groups based on various factors such as age, gender, race, ethnicity, among others.
2. An open system of social stratification allows for movement between social classes based on individual achievements and abilities, while a closed system of social stratification limits or prohibits such movement and is typically based on ascribed characteristics such as family background or birth.