Linux Shell Io redirection

I often see 1> & 2 similar statements in Linux shell scripts. What does this mean?

In fact, both of them are Linux file descriptors. in Linux

0 indicates standard input.

1 indicates standard output

2 indicates error output

Another special one is/dev/null.This is a bottomless pit, and no content redirected to it will be output.

1> & 2 indicates redirecting the standard output to the error output

1>/dev/null indicates no standard output content is output.

Note before and after the redirection symbolNo space