A nation is referred to a community of people who bond together as they share a common territory and a common government. The people in the nation form a nation irrespective of the diverse ethnicities, religions etc. There are a huge number of factors/ parameters based on which we may differentiate or classify the nations.
These factors include the population of the nation, the total area, the purchasing power, the GDP, the military personnel and many others. Any one or any combination of multiple of these factors can be used to classify these nations and form a list of the strongest nations in the world.
The United States of America stand on top of the list of the strongest nations in the world. The nation has a population of 316,149,000 people; the total area is 9,826,675 sp km, a GDP of $15.685 trillion and a purchasing power of 13,780,000,000,00 dollars.
The strength of the nations in this list is measured on the basis of a number of factors being considered to give one end result. A few of these factors are as mentioned along with the figures in the example above.
The other nations which make to the list of the strongest nations and follow the USA in the first position are China, Russia, India, United Kingdom and others.