In Unix-like systems, the pipe operator (|) is used to redirect the output of one command to the input of another command. It allows us to chain multiple commands together and process the output of one command as the input of the next command.  For example, consider the following command:  ls -l | grep "foo"  This command will list the files in the current directory using the ls command, and then filter the output to display only the lines that contain the string "foo" using the grep command. The output of the ls command is piped to the grep command using the | operator, allowing the grep command to process the output of the ls command as its input.  We can use multiple pipe operators to chain together multiple commands. For example:  cat file.txt | grep "foo" | sort | uniq -c  This command will display the contents of the file "file.txt" using the cat command, filter the output to display only the lines that contain string "foo" using the grep command, sort the output alphabetically using the sort command, and count the number of occurrences of each unique line using the uniq command with the -c option.  Overall, the pipe operator allows us to run several commands in one line by chaining them together and processing the output of one command as the input of the next. This can be a powerful and efficient way to manipulate data and perform complex tasks on the command line.