A population can be defined as a group of organisms of the same species that live in the same area (habitat) at a certain point of time. One of its characteristics is population density or the average number of individuals ( in that population) per unit of area. Since the individuals within population are not often spread evenly, population distribution describes how those individuals are distributed.
All the individuals of the same species living in a given geographical area is defined as population. The average number of individuals of a population living in a unit area is the population density of an organism. For example, if a population of 50 birds live in an area of 50 square meters, then a density of bird is 1 bird per square meter. Thus, population density is just the average number of individuals in a unit area. The individuals in a population is not uniformly distributed in a given area but they may be in small group or sparsely distributed. So, population distribution tells how the individuals are distributed in a given area.
