Sampling is the process of selecting a subset of individuals from a population to estimate characteristics of the whole population. It involves choosing a representative group from a larger dataset to make inferences about the entire population. Sampling techniques can be probability-based, such as simple random sampling, stratified sampling, and cluster sampling, or non-probability-based, such as convenience sampling and quota sampling. Proper sampling methods ensure that the sample accurately reflects the population, reducing bias and improving the reliability of statistical analyses and model training.