System.out.println() ?

System.out.println()System is a built-in class present in java.lang package.
This class has a final modifier, which means that, it cannot be inherited by other classes.
It contains pre-defined methods and fields, which provides facilities like standard input, output, etc.

out is a static final field (ie, variable)in System class which is of the type PrintStream (a built-in class, contains methods to print the different data values).
static fields and methods must be accessed by using the class name, so ( System.out ).
out here denotes the reference variable of the type PrintStream class.
println() is a public method in PrintStream class to print the data values.
Hence to access a method in PrintStream class, we use out.println() (as non static methods and fields can only be accessed by using the refrence varialble)
System.out.println();
eg: int i = 3;
System.out.println(i);

the above code prints the value of 3 in the screen and brings the control to the next line.

OR
'System' is a class in java.lang package'out' is a static object of PrintStream class in java.io
package
'prinln()' is method in the PrintStream class.....
since 'out' is a static object it can be called by using
the class name'system'
so 'System.out.println()'