What is difference between parameter and argument in java?

They are synonyms.

Some people use the Word 'argument' for the 'formal parameter' and 'parameter' for the 'actual parameter', others do on the other way around.

PS:

example for the formal parameters (function declaration):

int myfun (const char *s, int p);

example for the actual parameters (function calling):

myfun ("Hello", 44);