Is the primary key and auto increment the same?&??
no but it can be auto increment has all they basic property required for a primary key but it can be case that there are more than one auto increment columns or more than one distinct columns . here only one will be primary
A column can definitely be an identity without being a PK. An identity is simply an auto-increasing column. A primary key is the unique column or columns that define the row. These two are often used together, but there's no requirement that this be so.
The answer is no. For example you can create a table with passport number as primary key and without auto-increment condition. But when you want to create and ID column to sequentially identify each row is better to use auto increment than doing by yourself.
Yes and Not. Autoincrement can only be the primary key; but primary key can be other such as social id