Measures are quantitative, numeric data values that represent the metrics, facts, or numerical attributes of the data being analyzed. Unlike dimensions, which categorize or describe data, measures are used for performing mathematical operations and calculations. Measures can be aggregated, summarized, and used to answer questions like "how much" or "how many." Common examples of measures include sales revenue, profit margins, quantities sold, temperature readings, and any other numeric data that can be subjected to mathematical operations.
In Tableau, measures are typically placed on the Values shelf in a visualization, and aggregations and functions (sums, averages, counts, etc.) can be applied to them to generate meaningful insights and visual representations of the data used. Measures are a an importnat component in creating charts, vizuals, and calculations to analyze and display quantitative data effectively.
Here are some examples for a better understanding.
Sales Revenue: This is a classic example of a measure. It represents the total monetary value of products or services sold.
Profit Margin: Profit margin is a measure that calculates the profitability of a product or business by comparing revenue to costs.
Quantity Sold: This measure counts the number of units of a product sold.
Average Customer Rating: When analyzing customer feedback, you might use the average rating as a measure.