Attributes define a character's basic statistical capabilities. The four Basic Attributes are Strength, Dexterity, Intelligence, and Health and are defined on page 14 of Basic Set: Characters and page 4 of GURPS Lite .
The Secondary Characteristics are Damage, Basic Lift, Hit Points, Will, Perception, Fatigue Points, Basic Speed (which Dodge is based off of), and Basic Move. They are defined on the next few pages, along with information on Size Modifiers, Wealth, Tech Levels, and other basic statistics.