> operator redirects the output usually to a file but it can be to a device. You can also use
>> to append.
If you don't specify a number then the standard output stream is assumed, but you can also redirect errors:
> file redirects stdout to file
1> file redirects stdout to file
2> file redirects stderr to file
&> file redirects stdout and stderr to file
> file 2>&1 redirects stdout and stderr to file
/dev/null is the null device it takes any input you want and throws it away. It can be used to suppress any output.
> file 2>&1 is an older syntax which still works,
&> file is neater, but would not have worked on older systems.