What are PrecisionGoal and WorkingPrecision in Mathematica?

[Petar Mali]

What means

$$PrecisionGoal\rightarrow 6, WorkingPrecision \rightarrow 10$$?

Can you explain what here is this numbers $$6$$, and $$10$$?

 

[Bill Simpson]

http://reference.wolfram.com/mathematica/tutorial/ControllingThePrecisionOfResults.html

http://reference.wolfram.com/mathematica/ref/Accuracy.html

http://reference.wolfram.com/mathematica/ref/Precision.html