Population means the number of people who live in the same area or who belong to the same group. There are many population quotes on the Internet and these can involve various neighborhoods, cities, states, countries, or groups. When you look at a population you may be trying to determine the number of actual residents, the different activities, hobbies, or preferences of a group, or something else instead. A population explosion means that the number of people in the area or group has started increasing significantly. If the population for an area is high then each resident may find that space is becoming tight and the housing and services available may not be sufficient. Some countries have laws regarding population control due to over crowding and a population which has grown to enormous numbers.