There are probably three types of maps that are most commonly purchased by the layman who is not interested in having a poster on their wall showing mean precipitation or mineral wealth distributions for example.
Physical Map
The first of these three is called a physical map and it will show all the key physical features on the surface of the planet. Typically, these are coloured to broadly depict the true colour of the feature. The seas and oceans will be shown in blue, deserts as yellow, the snow and ice of the arctic as white and temperate regions of forest of grasslands as green for example. In addition, the main rivers of the world will be shown, and major mountain ranges too.
In terms of identification, the names of countries and political regions would tend not to be included. Instead, the names of rivers, seas, mountain ranges will. Also terms that describe other specific land features will be incorporated such as the West Siberian Plain, the Great Plains in North America or the Plateau of Tibet. The names of islands will be marked and these may well coincide with a country name, but the former is being referred to. Examples include Iceland or Madagascar.
In short, a physical map most closely mirrors what you would see when looking out of the window of an aeroplane and can in itself be a thing of beauty.
Political Map
The second type of map that is commonly purchased is a political map, showing the countries or states of the world. These are represented by largely arbitrary colours but distinct enough to clearly show the boundaries between countries. They would also tend to show towns and cities.
Topographical Map
Probably the most often requested map is a topographical map. This shows all the key features of the surface of the world. In so doing, it tends to incorporate key physical features such as the ones listed above, as well as countries, cities and town. In addition, it will highlight important communication types such as roads, railways and canals. It may depict sub state boundaries as well as those between countries. It may go in to detail that includes national parks, reservations, reservoirs, lakes and waterfalls.
The topographical map therefore tends to represent most of the key features, either manmade or not, that can be found on the planet. As a single option for the world map poster on your wall, it is ideal.