EA and Maxis have made the game files of The Sims 4 available for you to download, if you’ve pre-purchased the game.
By pre-loading, you can download all the game files and have them ready to play as soon as the game launches in your region. You will need to launch Origin and head to your Game Library, it should show a download button if the pre-load is available in your region. it’s rolling out as I write this.
The game comes out September 2 in North America, September 4 in Australia, Japan, and Europe, and September 5 in New Zealand, India, South Africa, and the UK.