What is the difference between execute and bindParam?

Question

PHP

Good day. I started to translate the site from php 5.6 to 7, I make requests like this:

$user =  $pdo->prepare("SELECT * FROM `users` WHERE `login`=? AND `password`=?");
$user->execute(array($login,$password));

However, this method is rarely indicated in the documentation and bindParam is written. Why? What is the difference? How to write correctly? Google didn’t ban me, I read the documentation, but I still didn’t understand the difference.

If you can write as I write, is it necessary to write an array in execute? I have one variable in many places:

$count_sites = $pdo->prepare("SELECT * FROM `sait` WHERE `category` = ? AND `hosts` > '0' AND `status` = '1'");
$count_sites->execute(array($cat['id']));

Answer 1

execute puts all parameters into strings and a query, for example, to paginate a view

...(select bla-bla-bla limit ?, ?)->execute([1, 10])...

will not work, since 1 and 10 are strings and need to be bound to int