Questions

Foreign keys are the columns of a table that points to the primary key of another table. They act as a cross-reference between tables.

In detail : A Foreign key is a field (or collection of fields) in one table that uniquely identifies a row of another table or the same table. In simpler words, the foreign key is defined in a second table, but it refers to the primary key or a unique key in the first table.

Sufi silsilas began to crystallise in different parts of the Islamic world around the twelfth century. The word silsila literally means a chain, signifying a continuouslink between master and disciple, stretching as an unbroken spiritual genealogy to the Prophet Muhammad. It was through this channel that spiritual power and blessings were transmitted to devotees. Special rituals of initiation were developed in which initiates took an oath of allegiance, wore a patched garment, and shaved their hair. Thus, all statements are correct.

The process of absorbtion of rain water by the soil on the earth is called infiltration. By this process, the rain water that falls on the soil becomes ground water.