try-catch blocks are used for exception handling. They allow you to gracefully handle exceptions (errors) that occur within a block of code.

Here's how it works:

try {
    // Code that may throw an exception
} catch (Exception $e) {
    // Exception handling code
}

• Try Block: The try block contains the code that may potentially throw an exception.
• Catch Block: The catch block is used to handle any exceptions that are thrown within the try block.
• Exception Object: When an exception is thrown, PHP creates an exception object that contains information about the error, such as its type and message.
• Throwing Exceptions: Exceptions are thrown using the throw keyword. You can throw built-in exceptions or create custom exception classes. 
   

Example:

try {
    // Code that may throw an exception
    $result = 10 / 0; // Division by zero
} catch (Exception $e) {
    // Exception handling code
    echo "An error occurred: " . $e->getMessage();
}

In this example:

• The try block attempts to perform a division operation that may result in a division by zero error.
• If an exception occurs (division by zero), PHP jumps to the catch block.
• Inside the catch block, we handle the exception by displaying an error message obtained from the exception object ($e->getMessage()).

Using try-catch blocks allows you to handle exceptions gracefully, preventing your script from crashing and providing better error handling in your PHP applications.