HTC
Usually, in order to update your device from one version of Android to another, you must receive an update from your carrier or the device's manufacturer.
Well, the first manufacturer to use Android is "HTC" , HTC dream was the first official device to run Android on 22nd October 2008.
Every platform (Windows, Linux, Mac, etc) requires its own driver programs for each hardware device. Drivers are written by the hardware manufacturer for each supported platform.
The name 'Android' describes the operating system, or OS, used by a mobile device to handle applications, access the internet, and manage stored data. The Android platform is considered to be the most powerful competitor for Apple's iPhone operating system.
There is no Android Website to be associated with, as such. However, you can link your Android device with your Google Account, enabling synchronisation between your device and the account. This can be done via your device's settings.
That depends on the DEVICE you are running Android on. It would be the screen size of the device.
HTC is a company, not a device. Most of HTC's newer phones are Android-based, using their own variation of the software known as Sense. It is often seen to be a more well-rounded version of the Android operating system while providing all of the benefits of the Android platform (including apps, account synchronisation and open source). Check the HTC website to make sure that the device you are looking at is Android, as they also produce some Windows Phone 7 and Qualcomm Brew devices.
It's a Twitter app that you can use on an android device.
Since you aren't specifying what phone manufacturer you have, the method of rooting varies from manufacturer to manufacturer. You typically will require a Windows or Mac desktop or laptop to be able to initially root your device. See the related link below for a resource you can do your search.
An Android smartwatch wearer does need an Android device to fully utilize it. It will not operate on an iPhone.
You may be referring to Android's operating system, which is software that runs an Android device and the apps.
The core benefit of rooting is that it gives you control on how your device is configured. People that have devices that have any carrier or manufacturer apps will root to either suppress or remove them completely. Some will go as far as flashing a customized ROM of a "pure" Android OS into their device. Because the Nexus 7 has Android OS without any manufacturer or carrier "bloat" onboard, it's up to the individual to decide if it's necessary to root.