SQL is a language used to set up, administer and use databases. Not all databases have to use it but many of the best known do. If you have ever used a graphical database management system where you click to set up and use a database SQL may be very different. However, underneath the same stuff is going on.
You do not need to know how to do queries yet but it might help to see what they look like. Here are a few SQL commands (known as queries) and what they do. Some of them you may never need to type as you will be shown an easier way.
Create a new table
CREATE TABLE `fred`;
Don't worry about the details but you can see this tells the server to create a new table called fred.
Change a table
ALTER TABLE `fred` ADD `bbb` INT
This adds a new field called bbb to a table and tells the server that it will hold integers (whole numbers).
INSERT INTO `fred` (`a`, `bbb`) VALUES ('Kettle', '2');
The table has had two fields added (a and bbb). This query will add a new record. It puts data into both fields (Kettle and 2).