The power of Unix-based operating systems (including GNU/Linux, BSD, and Mac OS X) is that you can pipe terminal commands together and write scripts with them.
Piping commands means to send the output of one command to the input of the next command. An example would be to use the grep command to find all of the lines in a logfile that contain the text Googlebot and then send those lines to the wc command to count them:
grep 'Googlebot' | wc -l
The output would be the number of lines that contain the text Googlebot.
Series of commands can also be put into scripts and reused. See below for a list of resources for learning about shell scripting.