Difference between close and Flush

do you mean close() and flush()?or close() and quit()

I mean flush() and close() ?

Flush() is a java function which is used to write files.

close() is a selenium webdriver function which closes the web browser they have nothing in common.

While i invoke bufferewriter,say for example,..

Bufferewriter bw =new BufferedWriter(new FileWriter(fw));
bw.write("Hello");


now this is will work only if I write bw.flush() or bw.close() . i have done this practically .
Now what is the difference between this two functions.

call write() and then flush() (to avoid content loss/flush the characters to the intended stream).

close() (used to releases any system resources associated with the stream)