SQL stands for Structured Query Language. Some people prefer to spell it out, S-Q-L, rather than pronounce it sequel [ˈsēkwəl]. SQL is a standard defined and maintained by the American National Standards Institute (ANSI) as well as International Organization for Standards – International Electrotechnical Commission (ISO/EIC). It comes in numerous variants. These are specific to database systems that implement the standard. There are also numerous SQL like languages.
I can tell you are excited to learn more. You should care about SQL if you care about data. SQL primarily functions to describe tables of data. It instructs the database system to create, modify, or retrieve some form of table. If you want to impress someone with your insight into computer science, you could research statefulness and understand how SQL manifests this concept by way of transactions.
If you really wanted to you could write some SQL that it in no way describes a table. Why find those cases just to prove a point that something doesn’t fit neatly into “tables”? If that were your aims why bother with SQL in the first place? There are plenty of other languages that focus entirely on other data structures.
Understanding tables will help you understand how you can use SQL. SQL has the keywords CREATE, ALTER, and DROP which can be used to make, change, and destroy tables. These keywords can make other objects like functions, stored procedures, and views (users, logins, triggers, audits, connections, … etc.). While technically not tables, they do exist as rows in tables. These keywords can also be used to make indexes which help table operations be performed more efficiently.
Often, a person will be working with tables that already exist. In these cases, the SQL keywords SELECT, INSERT, UPDATE and DELETE will be used to perform CRUD operations. CRUD stands for Create, Read, Update, and Delete. These operations are often being performed by multiple users simultaneously. This is an important consideration.
SQL is declarative. A user need not know how to create locks or latches, nor which algorithms most efficiently sort, sample, or join. SQL allows the user to declare the state they wish data to be in. The database platform determines based on the structures in play, the statistics available, and other factors how best to fill the request.
When operations are performed the database uses a more specific state transformation known as a transaction. In short, a transaction is an all or nothing operation. It allows multiple tables to be acted on such that the affected tables are in either a start or finish state. Transactions are said to be ACID compliant. They possess Atomicity, Consistency, Isolation, and Durability. They are self-contained. The state is either as it was or as it was intended. Transactions operate independent of other transactions. They are permanent once completed.
In short SQL is a language for working with data in database systems. SQL allows you to describe what you want and get it without worrying about a whole host of technical issues best left to software engineers, database architects and administrators.