How does the use of backticks versus string delimiters impact the execution and validity of SQL queries in PHP when querying a MySQL database?

When querying a MySQL database in PHP, using backticks around table and column names is the recommended practice as it ensures compatibility with reserved keywords and special characters. Using string delimiters (such as single quotes) can lead to syntax errors or vulnerabilities like SQL injection if the input is not properly sanitized.

// Using backticks for table and column names in a SQL query
$query = "SELECT `column1`, `column2` FROM `table` WHERE `column3` = 'value'";