die() and exit() in PHP: what is the difference and which one is better to use?

Hello everyone! I started learning PHP and came across two functions: die() and exit(). They seem to do the same thing — stop script execution. But I noticed that they are used differently in various examples. For instance, when working with databases, they often write:\n\n```php\n$result = mysqli_query($conn, $query) or die("Query error");\n```\n\nAnd in other places, they use exit():\n\n```php\nif (!$user) {\n exit("User not found");\n}\n```\n\nI tried replacing die with exit — the code works exactly the same. But what confuses me is: why does PHP have two identical functions? Maybe there are some subtle differences in performance, error handling, or behavior? Or are they just synonyms, like echo and print? Please tell me which option is better to use in real projects and if there is any difference at all.