Broken Pipe error

Hello

while doing sftp over server "A" , i am getting a broken pipe error i.e

cat: write error: Broken pipe

what does that mean? please let me know if you want any other info on this..

It means a program died unexpectedly and things further up the chain got killed when their pipes got broken from it.

can u expalin some more ?
and tell me the reason behind it?

First of all, "U" is not a word. I suspect you know how it's actually spelled and aren't posting from a telephone numpad.

program a is piped into program b. program b dies before program a can write everything it wants to write. program a gets killed with SIGPIPE.

It tells you nothing about why.