c++ - What is meaning of $g++ -std=c++11 main.cpp -o demo 2>&1 -

i want know meaning of following statement in unix -

$g++ -std=c++11 main.cpp -o demo 2>&1

call gnu c++ compiler:

g++

set language standard c++11:

-std=c++11

the input source file main.cpp:

main.cpp

set output (-o) filename demo:

-o demo

redirect (the > character) standard error (represented 2) standard output (represented 1):

2>&1

both standard error , standard output linked console screen default.

Maxid