Personal computer

A personal computer or PC is usually a microcomputer intended to be used by one person at a time, and suitable for general purpose tasks such as word processing, programming, sending messages or digital documents (comprising text, images, audio or video) to other computers on the network (E-mail), multimedia editing or game play, usually used to run software not written by the user. Unlike minicomputers, a personal computer is often owned by the person using it, representing a low cost of purchase and simplicity of operation. The user of a modern personal computer may have significant knowledge of the operating environment and application programs, but is not necessarily interested in programming nor even able to write programs for the computer.
In modern usage PC nearly always refers to an IBM PC compatible and the term may even be used for machines that are in no way personal computers but still use the basic architecture of the IBM PC.

Light Pollution

In urban areas light pollution can hide the stars and get in the way with astronomy. In settings near astronomical telescopes and observatories, low pressure sodium lamps may be used. These lamps are beneficial over other lamps such as mercury and halogen lamps because low pressure sodium lamps emit lower intensity, monochromatic light. Observatories can filter the sodium wavelength out of their observations and almost eliminate the interference from nearby urban lighting.The light pollution also disrupts the natural increasing cycle of plants.

Dinghy

A dinghy is a small utility boat attached to a larger boat. Dinghies are rowboats, or have small outboard motors —some use a small sailing rig. Dinghies are needed for any off-ship excursions from larger boats, outside of docking at suitably-sized ports or marinas.
When not in the above reference, a "dinghy" usually refers to a similar boat originally developed from that use, but now used in its own right for dinghy sailing or rowing.

Niagara Falls

Niagara Falls is a set of massive waterfalls situated on the Niagara River in eastern North America, on the border among the United States and Canada. Niagara Falls (French: les Chutes du Niagara) comprises three separate waterfalls: the Horseshoe Falls (Canadian Falls), the American Falls, and the smaller, nearby Bridal Veil Falls. The Falls are situated 16 miles (26 km) away from the U.S. city of Buffalo and 43 miles (69 km) from the Canadian city of Toronto. The distance to downtown Toronto is 80 miles (123 km) when using roads.
The Falls formed after the receding of the glaciers of the most recent Ice Age, as water from the newly created Great Lakes carved a path through the Niagara Escarpment enroute to the Atlantic Ocean. While not exceptionally high, Niagara Falls is very wide. With more than 6 million cubic feet (168,000 m³) of water falling over the crestline every minute in high flow, and almost 4 million cubic feet (110,000 m³) on average, it is the most powerful waterfall in North America.
Niagara Falls is not well-known only for its beauty. The Falls are a valuable source of hydroelectric power for both Ontario and New York. Preserving this natural wonder from commercial overdevelopment, while allowing for the needs of the area's people, has been a tough project for environmental preservationists since the nineteenth century. A popular tourist site for over a century, the Falls are shared between the twin cities of Niagara Falls, Ontario and Niagara Falls, New York.

Antarctic flora

The climate of Antarctica does not permit extensive vegetation. A combination of sub-zero temperatures, poor soil quality, lack of moisture, and lack of sunlight inhibit the flourishing of plants. As a result, plant life is limited to frequently mosses and liverworts. The autotrophic community is ended up of mostly protists. The flora of the continent mainly consists of lichens, bryophytes, algae, and fungi. Growth normally occurs in the summer, and only for a few weeks at most.
There are more than 200 species of lichens and approximately 50 species of bryophytes, such as mosses. Seven hundred types of algae exist, most of which are phytoplankton. Multicolored snow algae and diatoms are particularly abundant in the coastal regions during the summer. There are two species of flowering plants found in the Antarctic Peninsula: Deschampsia antarctica (Antarctic hair grass) and Colobanthus quitensis (Antarctic pearlwort).

Internet vs. Web

The Internet and the World Wide Web are not synonymous: the Internet is a collection of interconnected computer networks, linked by copper wires, fiber-optic cables, wireless connections, etc.; the Web is a collected works of interconnected documents and other resources, linked by hyperlinks and URLs. The World Wide Web is available via the Internet, as are many other services with e-mail, file sharing, and others described below.
The best way to define and differentiate between these terms is with reference to the Internet protocol suite. This collection of standards and protocols is ordered into layers such that each layer provides the foundation and the services necessary by the layer above. In this conception, the term Internet refers to computers and networks that communicate using IP (Internet protocol) and TCP (transfer control protocol). Once this networking structure is recognized, then other protocols can run “on top.” These other protocols are sometimes called services or applications. Hypertext transfer protocol, or HTTP, is the application layer protocol that relations and provides access to the files, documents and other resources of the World Wide Web.