Answer:
-Name must be unique
-Each relation must have columns
-Each row must be unique
-Columns must have unique name
Explanation:
Not all tables qualify as a relation. For a table to qualify as a relation, it needs to store the relation between the data and there are some requirements that need to be fulfill like: the name of attributes and tables can't be repeated, each relation should have a group of columns or attributes, a row can't be a duplicate and columns should have different names.