The mother of all hosts on the internet, the highest domain name, the beginning of all the other lower host names. Little is known that the dot precedes .com, .net, .org or .mil and so on and so forth, all of the .edu and .org connect to the dot, as in ".com." or ".mil.".

To make my point more clear, you can type: "" and get away with it. Legend has it that web browsers magically insert a dot for you at the end of every url.