A time series and a cross-sectional data set are two types of data commonly used in statistical analysis. They are collected and organized differently, and they are analyzed and interpreted differently.

**Time Series Data:**

A time series of data is a series of observations made at different points in time over a sequence of equally spaced time intervals. It involves observing a variable or multiple variables over a sequence of equally spaced time intervals.

There are many fields in which time series data can be used for analyzing trends, patterns, and forecasting future values, including finance, economics, meteorology, and social sciences.