How to properly work with PHP PDO?

Question

PHP

Hello! I'm reading a book on PHP and SQL (by David Sklar, page 201) which included this code:

$db = new PDO('sqlite:/tmp/restaurant.db'); //(1)
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION)
$q = $db->exec("CREATE TABLE dishes (
                         dish_id INT,
                         dish_name VARCHAR(255) //(2)
                            //ну и так далее
)");

Here are my own questions:
(1) - what is the 'sqlite:/tmp/restaurant.db' path? There was no mention of such files in the book. Is this the path that specifies where to write the created database? Or what is it? How to do the same with sql (and not with sqlite)?
This is the path to the data base. But how to create it? How to make sure that this path is correct?

Answer 1

1. sqlite - a simple database, roughly speaking, on files that works with SQL queries https://ru.wikipedia.org/wiki/SQLite, you do not need to connect to the database server with it, but you can use it almost immediately
   
2. yes, this is a string with a maximum length of 255 characters, if there is more, it will give an error