How is the Apple Watch connected to the Internet?

The Apple Watch uses the Internet for a lot of things : Siri answers, sending messages...

But how is the Apple Watch connected to the Internet ?

I have searched a bit, to no avail. This information must be too technical. ;-)

From the "Apple Watch User Guide"

Apple Watch uses Bluetooth® wireless technology to connect to its paired iPhone and uses the iPhone for many wireless functions. Apple Watch can’t configure new Wi-Fi networks on its own, but it can connect to Wi-Fi networks you’ve set up on the paired iPhone.

If your Apple Watch and iPhone are on the same network but aren’t connected by Bluetooth, you can also do the following on Apple Watch without iPhone:

• Send and receive messages using iMessage
• Send and receive Digital Touch messages
• Use Siri

The watch is using the Wi-Fi settings from you paired iPhone to access the internet. As stated above it can connect to networks you have set on the iPhone. The Bluetooth will connect to the phone and pass data back and forth.

Apple's press release for the Apple Watch says:

Apple Watch also features Wi-Fi 802.11b/g and Bluetooth 4.0 to pair seamlessly with your iPhone.

Though this doesn't precisely answer your question, it seems likely that the requirement for an iPhone indicates that the watch will only connect to the internet through the phone.

Edit:

Apple published a webpage with the title:About Bluetooth and Wi-Fi on Apple Watch

Your Apple Watch uses Wi-Fi and Bluetooth to communicate with your paired >iPhone, switching between connections as needed:

• Your Apple Watch uses Bluetooth when your iPhone is near, which conserves power.
• If Bluetooth isn’t available, Apple Watch will try to use Wi-Fi. For example, if compatible Wi-Fi is available and your iPhone isn't in Bluetooth range, Apple Watch uses Wi-Fi.

On this page you also can find information about the Compatible-Devices and how to check the Network on your Apple Watch.

Conclusion: The Apple Watch power is limited by it's battery, so Apple uses Bluetooth only, if the iPhone is in range, because Bluetooth4.0 is Low Energy. If you are (e.g) on the toilet and your iPhone in the living room, the Apple Watch uses your WiFi (if present) and also is able to communicate with you Phone over WiFi.

_{First original answer by me. no specs where published by Apple at this time:}

_{All signs pointing out that Apple Watch is connected via Bluetooth to your iPhone (5/5c/5s/6/6+) is required. Bluetooth, because the amount of Data isn't really high.}

This article Apple Watch Likely Uses BCM4334 Broadcom Wi-Fi Chip shows the Apple Watch supports both Bluetooth and Wi-fi but only uses them to connect to the iPhone.

Update from WWDC 2015: "Apple Watch can now communicate directly with known Wi-Fi hotspots using the new Tetherless Wi-Fi feature in watchOS 2”: