Cross-sectional data refers to information collected at a single point in time across various subjects, such as individuals, organizations, or countries. This type of data allows researchers to analyze and compare different characteristics or behaviors within a specific population, providing a snapshot of the situation at that moment. For example, a survey measuring the income levels and education of a group of people in a city can be considered cross-sectional data. It helps identify trends and relationships, but it does not show how these factors change over time, as it lacks longitudinal information.