Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. A population is the complete set group of individuals, whether that group comprises a nation or a group of people with a common characteristic. In everyday use the word population refers a group of people or a group of living beings.

Population definition in statisticians perspective:
In statistics, a population is the pool of individuals from which a statistical sample is drawn for a study. Thus, any selection of individuals grouped by a common feature can be said to be a population. A sample may also refer to a statistically significant portion of a population, not an entire population. For this reason, a statistical analysis of a sample must report the approximate standard deviation, or standard error, of its results from the entire population. Only an analysis of an entire population would have no standard error.
Statisticians refer to whatever group they are studying as a population. Statisticians and researchers prefer to know the characteristics of every entity in a population to draw the most precise conclusions possible. This is impossible or impractical most of the time, however, since population sets tend to be quite large.
the term world population is often used to refer to the total number of humans currently living, and was estimated to have exceeded 7.9 billion as of November 2021. It took over two million years of human prehistory and history for the human population to reach one billion and only 207 years more to grow to 7 billion.

There has been a rapid growth of the human population in the last century due to the difference in the birth rate and the mortality rates. In the next one decade, the population of the world is expected to grow by another billion. The impact of uncontrolled population growth impacts not just a section of the society, but the entire population suffers from its infinite impact on the economy and the environment.

The human overpopulation or population explosion is caused when the ecological footprint of humans in a particular region crosses the actual carrying limit of the place with regards to space and the resources available. A place is considered to be overpopulated if the existing population in the area can no longer be maintained due to the constant depletion of the non-renewable resources or the natural resources leading to a degradation of the environment. However, a change in the lifestyle and the consumption and the use of renewable resources can help reverse the effects of population explosion without an actual or substantial decrease in the population.
The population of the world has increased exponentially in the past few decades. Around the year 1810, the population of the world was 1 billion. Just about a century later the population doubled to 2 billion, it increased to 4 billion in the next 45 years (1975) and by January 2019 the current population has reached 7.7 billion. The carrying capacity of the earth is 4 billion to 16 billion. It can be said that population explosion or human overpopulation may have already occurred on the Earth. According to the recent estimates, the world population would have reached somewhere around 10-11 billion between the years 2014 and 2050.

The effect of population explosion is multi-layered. It not only impacts the environment and the availability of resources but it also impacts the health of individuals within the population.
Natural resources are depleting constantly with the increasing demand and consumption. Fossil fuel which is the primary source of energy that drives the technology-driven world is fast depleting. Which poses a very important question on what do we depend on once this natural resource has exhausted. Although there is growing awareness on the use of renewable energy like biofuels, solar, wind and tidal energy and others there is still a long way to go where these renewable resources can actually replace the use of fossil fuels.
With the increasing population and the rising demand, there is an increased level in the air, water and soil pollution. This is not only impacting the lives of humans but has also affected the lives of many animals resulting in the endangering of many species and the extinction of many. The high levels of pollution have resulted in contamination of water and soil that has rendered many patches of land and water bodies unfit for use. Drinking water is fast becoming inadequate to support the needs of millions of people. With the increase the demand for crops to meet the global food requirements there has been an increase in deforestation to provide for agricultural land. This has led to a significant contraction in the biodiversity of many regions. Deforestation, on the other hand, has serious repercussions on the climatic condition of the planet. It leads to an increased level of carbon dioxide which is one of the contributing factors to global warming.
Apart from the environmental effects there is a huge socio-economic impact as the countries resources become inadequate to support the needs of a growing population. Countries with high population have high unemployment percentages as well which means that a greater number of people live in poverty, incapable to support the needs for sanitation and health care. It not only means malnutrition but it also leads to increased incidences of epidemics and pandemics.
Living conditions become increasingly compact and crowded which is detrimental to a thriving society and good mental health. It breeds crime and antagonism and higher mortality rates. Overpopulation impacts the entire biosphere as it impacts the environment in multiple levels.

The most important way to control a steady rise in population is by education and empowerment. The impact of population rise awareness should be created among the people.Awareness about the available sources and its consumption, also its concern about providing a quality life to the current and future generations. Birth control and family planning is the first step that needs to be taken to ensure a gradual decline in the growth rate of the population. About 40% of worldwide pregnancies are unintentional which can be avoided by the use of oral contraceptives or other birth control devices like condoms or intrauterine device. About 350 million women in the developing countries of the world are unaware of birth control options or the possibilities for family planning. Educating these women and making access to the birth control devices affordable can help in not only controlling the population growth but also help to improve the quality of life for these women and their children. Many countries promote small size families limiting the number of children per family to two or fewer. Male sterilization is also promoted to help in birth regulations. This has been made effective in a number of countries and a positive impact has been seen in the growth rate of the population of those countries.
Urbanization is another proposed method to help combat over population. According to the United Nations Human Settlements Program (UN-Habitat), urbanization may be an effective option for controlling the population growth. It suggested that cities tend to concentrate human activity with a limited area thus substantially reducing the breadth of environmental damage that is caused by a growing population. This can be achieved by efficient urban planning and proper maintenance of city services assuring an acceptable quality of life to its dwellers.

The overpopulation may exploit the extraterrestrial settlements or space habitats that could support life forms.It is our responsibility to save,protect and provide our future generations a better life so we need to control the poluation in order to reduce the overusage of resources.