standard output
also: stdout, fd 1, file descriptor 1
Standard output (stdout) is the default destination where a program sends its normal text output, typically the terminal display. It is represented by file descriptor 1 in Unix/Linux systems.
Standard output is one of three standard I/O streams available to every process. By default, it displays text on your terminal, but it can be redirected to files or piped to other programs using the shell's redirection operators.
In the command ls -la > listing.txt, the > operator redirects stdout from the terminal to a file. Similarly, in cat file.txt | grep "error", the pipe | connects one program's stdout to another's stdin (standard input).
Stdout is distinct from standard error (stderr, file descriptor 2), which is used for error messages and warnings. This separation lets you handle normal output and errors differently—for example, saving output to a file while still seeing errors on the terminal.