In all three types of cluster sampling, you start by dividing the population into clusters before drawing a random sample of clusters for your research. The next steps depend on the type of cluster sampling:
Single-stage cluster sampling: you collect data from every unit in the clusters in your sample.
Double-stage cluster sampling: you draw a random sample of units from within the clusters and then you collect data from that sample.
Multi-stage cluster sampling: you repeat the process of drawing random samples from within the clusters until you’ve reached a small enough sample to collect data from.