Question: I want to clarify difference between sequel vs SQL? Any one here know the difference between them?

Answer: 
in the early 1970s. Initially called SEQUEL (Structured English Query Language) and based on their original language called SQUARE (Specifying Queries As Relational Expressions).SEQUEL was later renamed to SQL by dropping the vowels, because SEQUEL was a trade mark registered by the Hawker Siddeley aircraft company.
They are the same.

From [Wikipedia](http://en.wikipedia.org/wiki/SQL): 

> 
> **SQL** (/ˈɛs kjuː ˈɛl/ "S-Q-L"[4]; Structured Query Language[5][6][7][8])
>  is a special-purpose programming language designed for managing data
>  held in a relational database management system (RDBMS).
> 
> 
> 

Some people pronounce it "S-Q-L", while others pronounce it "sequel".

For more on the pronunciation of this term: 

**<https://english.stackexchange.com/questions/7231/how-is-sql-pronounced>**

<http://patorjk.com/blog/2012/01/26/pronouncing-sql-s-q-l-or-sequel/>