Tayammum is performed by striking the hands on clean soil or dust and then passing them over the face and hands. The ritual is performed in place of the wudu (ablution) or ghusl (full body wash) which are typically performed with water.
According to Islamic teachings, tayammum is a permissible alternative when water is not available or when its use is harmful to a person's health, such as when there is a risk of illness or when the water is contaminated. Tayammum is also recommended for travelers who may not have access to clean water or who may be in areas where water is scarce.
Overall, tayammum is an important practice in Islam that allows Muslims to maintain their ritual purity even when water is not readily available or cannot be used. It is seen as a practical solution for situations where water is scarce or unavailable, and is a reminder of the importance of cleanliness and purity in Muslim life.