Column as an expression for CALCULATE?

[Anonymous]

 CALCULATE ( <expression> , <filter1>, <filter2>, ...)

This is the Syntax for the CALCULATE function in DAX and it is said that 

expression can be a measure or a calculation that you’d want to evaluate.

However, I see things like

CALCULATE ( [Sales], PARALLELPERIOD ( 'Date'[Date], -12, MONTH ) )

where I think that [Sales] is a column.

(See here: Verwenden von Variablen zur Verbesserung der Leistung und zur Problembehandlung - Training | Microso...)

So my question is: How is that possible?

In which way is a column like [Sales] a measure or calculation?

[tamerj1 · Accepted solution]

@Anonymous 
It should be a measure

[tamerj1 · Accepted solution]

@Anonymous 
It should be a measure

[Anonymous · Accepted solution]

Hi,

then maybe this is just bad notation. Because for me it looks like a column.