Input and Output Redirection in Linux

Standard Input - 0
Standard Output - 1
Standard Error - 2

> - Output Redirection
< - Input Redirection

# Send an error when file doesn't exist
ls -l myfile.txt 2> test.txt (/bin/ls: adad: No such file or directory)

2>&1 (redirect input and error) into normal file
ls -l xxx.txt 2>&1 another_file