In simple terms, population means the aggregate of all elements under study having one or more common characteristic, for example, all people living in India constitutes the population. The population is not confined to people only, but it may also include animals, events, objects, buildings, etc. It can be of any size, and the number of elements or members in a population is known as population size, i.e. if there are hundred million people in India, then the population size (N) is 100 million.
Definition of Sample
By the term sample, we mean a part of population chosen at random for participation in the study. The sample so selected should be such that it represent the population in all its characteristics, and it should be free from bias, so as to produce miniature cross-section, as the sample observations are used to make generalisations about the population.
Key Differences Between Population and Sample
The difference between population and sample can be drawn clearly on the following grounds:
The collection of all elements possessing common characteristics that comprise universe is known as the population. A subgroup of the members of population chosen for participation in the study is called sample.
The population consists of each and every element of the entire group. On the other hand, only a handful of items of the population is included in a sample.
The characteristic of population based on all units is called parameter while the measure of sample observation is called statistic.
When information is collected from all units of population, the process is known as census or complete enumeration. Conversely, the sample survey is conducted to gather information from the sample using sampling method.
With population, the focus is to identify the characteristics of the elements whereas in the case of the sample; the focus is made on making the generalisation about the characteristics of the population, from which the sample came from.