Discuss the differences between an equi-join, natural join and outer join

What will be an ideal response?

Both a natural join and an equi-join create a join based upon equality between some common columns. While the equi-join keeps the redundant columns that are used for the match, the natural join removes duplicates. There are situations where one table may contain information that is not in the other table. However, it is necessary to display both matching data as well as records which do not have a match in the second table. This situation is where we would use an outer join.