Microsoft Exam DA-100 Topic 1 Question 43 Discussion

Combining data means connecting to two or more data sources, shaping them as needed, then consolidating them into a useful query.

When you have one or more columns that you'd like to add to another query, you merge the queries.

Note: The RELATEDTABLE function is a shortcut for CALCULATETABLE function with no logical expression.

CALCULATETABLE evaluates a table expression in a modified filter context and returns A table of values.

https://docs.microsoft.com/en-us/power-bi/connect-data/desktop-shape-and-combine-data