COUNTIF for Array

I'm trying to find a way to do a COUNTIF on two arrays to return the total number of entries that are not the same.
In the attached example, the formula should return a value of 2 in the yellow highlighted cell when comparing the blue and orange columns.

Try

=SUMPRODUCT(--($A$2:$A$6<>B2:B6))

That works. Thank you.

For my own knowledge, what function does the "--" perform?

You're welcome.

-- converts True/False responses to 1/0 responses
True = 1
False = 0