Assigning property values, Cascading, and Inheritance: "6 Assigning property values, Cascading, and Inheritance"
6.1 Specified, computed, and actual values
Once a user agent has parsed a document and constructed a document tree, it must assign, for every element in the tree, a value to every property that applies to the target media type.
The final value of a property is the result of a four-step calculation: the value is determined through specification (the "specified value"), then resolved into a value that is used for inheritance (the "computed value"), then converted into an absolute value if necessary (the "used value"), and finally transformed according to the limitations of the local environment (the "actual value").
Having not used CSS for a while, it is important to go back and jog the memory about specificity.