What do you know about Random Sampling and Non-random Sampling?

Random Sampling : Random sampling is one where the individual units from the population (samples) are selected at random. In the random sampling every individual has an equal chance of being selected and the individuals who are selected are like the one's who are not selected. For example, if the government wants to determine the impact of the rise in petrol price on the household budget of a particular locality. For this a random sample (representative) of 30 households has to be taken and studied. The names of all the 300 households of that area are written on pieces of paper and mixed well, then 30 names to be interviewed are selected by one by one. In random sampling every individual has an equal chance of being selected and the individuals who are selected are just like the one's who are not selected. Non-random Sampling: In a non-random sampling method all the units of the population do not have an equal chance of being selected and convenience or judgement of the investigator plays an important t uie in selection of the sample. They are mainly selected on the basis of judgement purpose, convenience or quota and are non-random samples