Material hardness refers to a material's resistance to deformation, scratching, or indentation. It is an important property in engineering and manufacturing, as harder materials are often more durable and wear-resistant. Hardness can be measured using various scales, such as the Mohs scale, which ranks minerals based on their ability to scratch one another. Different testing methods, like the Brinell and Rockwell tests, provide quantitative values for hardness. These tests involve applying a specific force to a material and measuring the size of the resulting indentation. Understanding hardness helps in selecting the right materials for specific applications, ensuring longevity and performance.