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.

When did sequel become SQL?

By 1974 they published the query language SEQUEL (Structured English Query Language) based on SQUARE. Unfortunately, due to trademark violations on the acronym SEQUEL, which was already registered by the Hawker Siddeley aircraft company, the name was changed to Structured Query Language and abbreviated as SQL.

Is it MySQL or my sequel?

The official way to pronounce “MySQL” is “My Ess Que Ell” (not “my sequel”), but we do not mind if you pronounce it as “my sequel” or in some other localized way.