Final answer:
Continents are large landmasses with a distinctive continental shelf, classified into various biogeographic realms, while coastal areas refer to regions near the boundaries of continents and include marine biomes such as coral reefs and estuaries. Each has specific bio-geographical realms and offers unique geographic and demographic opportunities and challenges.
Step-by-step explanation:
The distinction between continents and coastal (marine) areas is essential in understanding Earth's biogeographic realms and geographical features. Continents are large landmasses that are identified by the extent of their continental shelf, which is a submerged prolongation of the continent that reaches out to a point where there is a significant change in slope.
These are often demarcated by the fossil evidence found along the edges of the continental shelf. In contrast, coastal or marine areas are those parts of the ocean that lie close to the continents and include diverse environments such as coral reefs, estuaries, and the continental shelf itself.
Bio-geographically, continents are categorized into realms like Australasia, Antarctic, and the Neotropic, among others. Marine coastal areas, however, have been divided into 12 different realms such as the Temperate North Atlantic and Western Indo-Pacific. These realms categorize regions according to common environmental and ecological characteristics, providing a framework for comparison and analysis.
Geographical and demographic differences among countries are influenced by whether they are landlocked or have access to the sea, as well as the presence of other natural features such as rivers and mountains. Coastal areas have unique opportunities and challenges, including commerce, health, and environmental aspects. It is also important to note that many coastlines are protected from waves by orientation or the lack of exposure to open stretches of water, which can affect the biome and its characteristics. The marine biome, including the ocean and coral reefs, forms the largest and one of the most complex biomes on Earth.