A permutation test is a statistical method used to determine if there is a significant difference between two groups. It works by rearranging the data points in the groups to create a distribution of possible outcomes. By comparing the observed difference to this distribution, researchers can assess the likelihood of obtaining such a difference by chance. This non-parametric test is particularly useful when the assumptions of traditional tests, like t-tests, are not met. It can be applied to various types of data and is often favored for its simplicity and flexibility in analyzing complex datasets.