System.out.printf vs System.out.format

Are System.out.printf and System.out.format totally the same or perhaps they differ in somehow?

System.out is a PrintStream, and quoting the javadoc for PrintStream.printf

An invocation of this method of the form out.printf(l, format, args) behaves in exactly the same way as the invocation out.format(l, format, args)

The actual implementation of both printf overloaded forms

public PrintStream printf(Locale l, String format, Object ... args) {
    return format(l, format, args);
}

and

public PrintStream printf(String format, Object ... args) {
        return format(format, args);
}

uses the format method's overloaded forms

public PrintStream format(Locale l, String format, Object ... args)

and

public PrintStream format(String format, Object ... args)

respectively.

No difference.They both behave the same.

The key difference between printf and format methods is:

• printf: prints the formatted String into console much like System.out.println() but
• format: method return a formatted String, which you can store or use the way you want.

Otherwise nature of use is different according to their functionalities. An example to add leading zeros to a number:

int num = 5;
String str = String.format("%03d", num);  // 005
System.out.printf("Original number %d, leading with zero : %s", num, str);
// Original number 5, leading with zero : 005