As we have already seen earlier in this chapter, the DAX language consists of a large number of functions that can be grouped based on the type of functionality they provide. In this section, we are going to take our first detailed look at these groups, starting with a look at the aggregation group of functions.
Aggregation functions provide a way to summarize or group data and common examples include the AVERAGE, COUNT, MAX, MIN, and SUM functions. All of these have their equivalent X function, such as SUMX. Instead of working against a column of a table, these X functions apply the aggregation to the result of an expression that is evaluated for each row of a table.
