What is the meaning of TIMESTAMP and NULL in a Postgresql table?

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TIMESTAMP is a data type in Postgresql that represents a date and time. It is used to record the exact time and date when a particular action took place in the database.

NULL is a special value in Postgresql that indicates that a particular cell in a table does not have any value or information. It is typically used to represent missing data or to indicate that a certain field is optional. When a cell in a table contains NULL, it means that there is no information available for that particular field in the database.