What is this formula saying?

[equinex3]

Someone built me a spreadsheet that yields results of MPH, Units/Mile, etc. Here's the formula that is used: =IFERROR((SUM(Averages!D12:I12)/COUNTIF(Averages!D12:I12,">0")),"")

I would like to know what the formula is saying.

Thanks in advance for your answer.

 

[vds1]

Taking the average of cells which is greater then zero. If the result yields error then its a blank

Example : 0 0 0 1 2 0

=3/2
=1.5