The words; World, Earth, Universe, Cosmos are quite frequently used interchangeably when we speak or write in a casual manner. If we do look closely, however, we will find that the terms are used in different connotations.
The term ‘World’ was originally derived from the Old English words “weorold” or “worold.” Now Wer itself implies Man or Human (as used in Werewolf) and Eld is believed to signify Age or time period. This means World quite literally translates into the Age of Man, or the time that represents human existence on this planet.
We see that the term “World” is quite often used (in social sciences) to represent mankind as a whole, and with reference to the different human civilizations of this world. In a religious or theological sense too, the word refers to human existence (as opposed to the Divine or Spiritual realms). “End of the World” theories highlight the usage of the term World. By this, we certainly do not mean the destruction of planet Earth, but the end of human civilization as we know it. On a very personal level, “World” is used to describe the human experience. For example, when we refer to someone as the “center of our world,” we emphasize their importance in our lives experience.
The word “Earth” is used specifically to denote the celestial body that forms the third planet from the Sun in our solar system. There are innumerable galaxies in the Universe and innumerable solar systems in our own galaxy, the Milky Way. The only planet that we know of to hold any form of life is the one that we live on – the Earth. This term is used more in an astronautical or astronomical sense. Through the evolution of language, however, we find it increasingly common to use the term Earth to mean the planet and all its living forms. Sometimes, we also refer to the land and water masses and all of life that this planet holds collectively as the Earth. The planet Earth, also referred to as the Blue Planet (due to the presence of water) is believed to have formed over 4.5 billion years ago. The word Earth derives its origins from the Old English term “eorðe” which is believed to have represented land or soil.
Let us also quickly touch upon the uses of the words Universe and Cosmos in this context. The term Universe essentially refers to everything that exists. This includes matter as we know it, but it also includes dark matter, energies, time, and space. It is commonly used in the astronomical sense to refer to space, the stars and galaxies that make up this space, and the matter and energy in this space. The term ‘universe’ is believed to have been derived from the Old Latin word ‘Univorsum.’ Uni represents One or single and Versum means something that rotates or rolls on. One of the most widely acknowledged theories about the origin of the Universe is the Big Bang Theory and the Universe is believed to be ever-expanding. Now, while the word Cosmos is strictly speaking a synonym of the word Universe, it is loosely used to describe stars, galaxies, and celestial events.
Another word that is often used interchangeably with these is Globe. A globe is a minuscule representation of the planet Earth and may be used to mark the physical features or political units such as countries that are in it.