EF: Peg Dawson's website and books:

http://www.smartbutscatteredkids.com/

In short, mental regulation and organization skills.

Working memory can be compared to your mental scratch paper--how much data a person can hold in his/her head, manipulate, and then either send to long-term storage or use to produce an external product.

...pronounced like the long vowel and first letter of the alphabet...