While the value of the Apple shares you own hasn't changed at all, the split does make it less expensive for the average investor to buy 100 shares. This additional demand is supposed to drive up the value of the stock.
For Apple, this is the first split that it has had in nine years, which means that it is the first split that Apple's shares have had since the launch of the Apple iPhone on June 29th, 2007. Adjusted for the stock split, Apple closed on June 29th at $16.66. That means that since the launch of the very first iPhone, Apple's shares have risen over five fold.
The first Apple iPad was launched on April 3, 2010. The last trading day before the tablet was launched, Apple closed at $32.22, meaning that the shares have nearly tripled since Apple created the tablet category.