Cannot differentiate between a primary key and a Super key

[GOOL]

I am a undergraduate student , but I am looking forward to be a DBA and for that purpose I want to make its relevant subject strong, so I have come today about a query regarding the tables and its construction , whenever I try to understand this tables and entities I always get confused regarding the keys , so it will be very much helpful if any one can any one explains about the the primary and the superkey, I think they are same keys. Please help me.

[Shreevats]

A primary Key which uniquely recognizes a row of table,primary key does not permit null values and neither will permit you to have duplicate or redundant values. Superkey is described in the relational model of database group as a set of attributes of a tabular variable for that it grasps that in all relations allocated to that variable there are no two different rows) that posses the similar values for the attributes in this collection .

[Steyn]

Equally a superkey can also be described as a set of attributes of a relational variable upon which all attributes of it are functionally reliant. fundamental dissimilarity in a primary key and Super key is that inPrimary key,we utilize only a one attribute to recognize a row, whereas in,Super key,we make use of dissimilar set of attributes to recognize any row in table .

[Author]

Different set of attributes which are capable of recognizing any row in the database is called as a super key. And least super key is named as a candidate key i.e. in the middle of set of super keys one with least number of attributes. Primary key can be any key which is able to recognize a particular row in database in a unique way. The primary keys are the keys that are unique and does not have null values.

[Dwarner]

Superkey is any part of attributes that exclusively recognize the rows of a table. This subset does not require to be least, that is, one can eradicate some attributes from it and it is still exclusively identifying. If all duplicates attributes are erased you get a subset what is referred as primary key. You can not remove more attributes from this subset if you do not loose the property of exclusive Identification.