A/B testing, also known as split testing, compares two versions of something (such as a website or a marketing email) to determine which one performs better. In an A/B test, a sample of users is shown one version (the "A" version), while another sample of users is shown the other version (the "B" version). The test results are then used to determine which version is more effective. A/B testing is commonly used in marketing and product development to improve the performance of a product or service. **Declaration:** This content is [[human-made and ai-assisted]].