What do you think of the way SQL joins tables together? You can join tables in ways the database designer didn’t foresee so you can extract information hiding in the data. Ad-hoc querying is a big reason that relational databases are so flexible.
From two sets of data it is an instruction to combine those two sets of data.Here Using join keyword we are joining the two tables.We will discuss why it is important.Take an example in a store one customer purchased one product on purticalur date. This information will record in the database.We know that in databse we have so many tables and in that we should want only the information about the customer name and purchase item and purticular date.
So here sql join used to combime those tables and join operation used to get the data only what are the tables you are selected.So in my view these are so important topic means very important activity while retreiving customer information from the bundle of tables.Withput this the join opeartion wont posssible and takes much time to retrieve the information.
Coming to relational database the main heart of this concept.By using this relational database you can save this information in tables represent two distinct entities.You can organize the data in purticaul format using this Relational databsae.