Opinion polls as a way of sampling

Today mention an error that is usually found frequently in the literature on surveys and opinion polls.
The same is to confuse all the surveys for opinion polls or social surveys. If we wish to clarify what is a survey, or provide a definition, we must make it clear that by no means something that applies to people necessarily.
In fact, the survey is a technique of data collection (some might question how far the data are "collected" as one who takes something that's already been out there and are not created, at least to some extent by those who do research, but that is another problem that will address later) that derives or is an application of the sampling procedure.
Specifically is the use of certain standardized and validated procedures under which the research takes information on a representative sample of a population or universe, as is usually called the total haw investigated.
It is clear that the purpose of such research procedures is to improve our insight of some phenomenon, say a good explanation.
One can conduct a survey in which sample is selected books from a library upon which a questionnaire is completed in some information, because what matters is that the procedure and representative sample.
This, as already mentioned, results from the application of the mathematical theory of probabilities to the investigation of phenomena, whether or not social.
A sample survey differs from a census in which it is to administer a questionnaire to all people concerned, while the survey is always applied to a sample, the best representative.