A t-test is a statistical method used to determine if there is a significant difference between the means of two groups. It is commonly employed in hypothesis testing to assess whether the observed differences in sample data reflect true differences in the population. The t-test operates under the assumption that the data follows a normal distribution and is particularly useful when sample sizes are small. There are different types of t-tests, including one-sample, independent two-sample, and paired sample t-tests, each serving specific research scenarios. Understanding t-tests is essential for data analysis in various fields, including psychology, medicine, and social sciences.