Touch screen

A touch screen is a display which can detect the presence and location of a touch within the display area. The term generally refers to touch or contact to the display of the device by a finger or hand. Touch screens can also sense other passive objects, such as a stylus. However, if the object sensed is active, as with a light pen, the term touch screen is generally not applicable. The ability to interact directly with a display typically indicates the presence of a touch screen.

Until the early 1980s, most consumer touch screens could only sense one point of contact at a time, and few have had the capability to sense how hard one is touching. This is starting to change with the commercialization of multi-touch technology.

The touch screen has two main attributes. First, it enables you to interact with what is displayed directly on the screen, where it is displayed, rather than indirectly with a mouse or touchpad. Secondly, it lets one do so without requiring any intermediate device, again, such as a stylus that needs to be held in the hand. Such displays can be attached to computers or, as terminals, to networks. They also play a prominent role in the design of digital appliances such as the personal digital assistant (PDA), satellite navigation devices and mobile phones.

Text input

For text input, the device implements a virtual keyboard on the touchscreen. It has automatic spell checking and correction, predictive word capabilities, and a dynamic dictionary that learns new words. The predictive word capabilities have been integrated with the dynamic virtual keyboard so that users will not have to be extremely accurate when typing—i.e. touching the edges of the desired letter or nearby letters on the keyboard will be predictively corrected when possible.

The keys are somewhat larger and spaced farther apart when in landscape mode, currently available using the Safari web browser and certain third-party applications with Landscape Mode support. A lack of focus on text-messaging is widely considered a chief weakness of the iPhone, although a large number of users evidently have no issue using the device for this purpose. The lack of a physical keyboard allows for the keyboard to be optimized for different applications and languages via software changes only, instead of requiring a costly additional fabrication process

Storage

The iPhone was initially released with two options for internal storage size; either a 4 GB or 8 GB flash drive (manufactured by Samsung) model was available. On September 5, 2007, Apple announced they were discontinuing the 4 GB models. On February 5, 2008, Apple announced the addition of a 16 GB model to the iPhone lineup. The iPhone does not contain any memory card slots for expanded storage.

Drinking Water

Every living creature needs clean and safe drinking water. How much do you need? It depends - your size, activity level and the weather all make a difference.

The water you drink is a combination of surface water and groundwater. Surface water includes rivers, lakes and reservoirs. Groundwater comes from underground. The United States has one of the safest water supplies in the world, but drinking water quality can vary from place to place. It depends on the condition of the source water and the treatment it receives. Treatment may include adding fluoride to prevent cavities and chlorine to kill germs.

Your water supplier must give you annual reports on drinking water. The reports include where your water came from and what contaminants are in it.