One of the links in the original article, actually points to a StackExchange answer specifically commenting on the difference between single instance and single

One of the links in the original article, actually points to a StackExchange answer specifically commenting on the difference between single instance and singleton. It's a great read. http://programmers.stackexchange.com/a/40610/42446 http://programmers.stackexchange.com/a/40610/42446