The User Account Control <span>dialog box in windows vista appears each time a user attempts to perform an action that can be done only with administrative privileges.</span>
This is called a key attribute!
There are different types of key attributes!
Primary key is the key that is actually chosen, for example a social security number.
There is also a unique key, say our finger prints! they also uniquely identify humans, but usually we prefer to use social security number when we list people (a unique key could be a primary key if we chose so)
We could also identify people by their social security number and a name, but this is unnecessary, as social security number already gives a full identification. Such a reduntant key is called super key.
a hard drive is a metal disk constantly spinning while powered on.
The data is written with a metal scratching the data onto the wheel.
Explanation:
i think cpu needs to have backup chache units in case of electrical failure
