The "tail" command is a function I use multiple times during a day. You use this command to get contents from a file. I often use it to get the last 10 entries in a log file.
To get the 10 last lines, you do this:
If you want to get the last 50 lines, you can add a parameter like this:
tail -n 50 error.log
But an equal important usage of "tail" is that you can "follow" the end of the file. Let say that you want to check the outputs of a log file when you open a website.
tail -f error.log
To achieve this, you add the "-f" parameter. Doing this, all the contents that comes into the file will be outputted to the screen until you stop the process.