Measures are the numerical values that quantify the data set that you want to dig into. They’re usually fields containing quantitative information. For example, a sales revenue column is a measure because you can find the sum or average the data. You can think of these as the y-axis in a chart.
Dimensions are how you want to categorize or break up the data. They’re usually fields that cannot be aggregated and contain qualitative, categorical information. For example, sales region, employee, location, or date are dimensions. You can think of these as the x-axis in a chart.