A sample is a small portion or unit of something that is measured to make a general statement about the whole thing. Technically speaking, items that researchers collect for performing their research work are known as samples. These units or samples represent the larger group from which they are selected. The basic process of selecting samples is called sampling. Sampling makes studying different characteristics of a large, heterogeneous population possible. It reduces the study population to a reasonable size, thus, greatly reducing the research expenses and speeding up the research process. It helps to finish any research within a reasonable period of time. Sampling provides true, valid, accurate and reasonable data. It also saves the consumption of all data resources. Sampling targets a specific small population and provides precise and typically accurate results.