Testing kits are tools used to determine the presence or absence of specific substances, such as diseases, chemicals, or other materials. They often include various components like reagents, instructions, and sample collection tools. Common examples include COVID-19 testing kits, pregnancy tests, and water quality testing kits. These kits are designed for ease of use, allowing individuals to conduct tests at home or in a laboratory setting. Results can often be obtained quickly, making them valuable for early detection and monitoring. Many testing kits are regulated to ensure accuracy and reliability, providing essential information for health and safety decisions.