What role do backticks play in MySQL queries and how should they be used in PHP?

Backticks are used in MySQL queries to wrap around table and column names to avoid conflicts with reserved keywords. In PHP, backticks should not be used to wrap around table and column names in queries, instead, single quotes or double quotes should be used.

$query = "SELECT * FROM `table_name` WHERE `column_name` = 'value'";