The Student's t-test is a statistical method used to determine if there is a significant difference between the means of two groups. It is particularly useful when the sample sizes are small and the population standard deviation is unknown. The test calculates a t-value, which is then compared to a critical value from the t-distribution to assess significance. There are different types of t-tests, including the independent t-test for comparing two separate groups and the paired t-test for comparing two related groups. The results help researchers understand if observed differences are likely due to chance or if they reflect true differences in the populations being studied.