The Website Job checks for the availability of a website. If the website is available, that is, the result code is between 100 and 299, the result is true, otherwise, it's false.
e.g. If you wanted to check, every 30 minutes, to make sure that the website www.rocksoftware.co.uk was available, you would do as follows:
1) Make sure that there was a RoCKNet Agent installed and running on the server FILESVR1 (only required once per server)
2) Create a new "Website Job" as shown below: