php сессии и как сохранять - SERP Analysis

https://www.php.net/manual/ru/session.examples.basic.php

https://metanit.com/php/tutorial/4.3.php

https://ru.stackoverflow.com/questions/1153449/%D0%9A%D0%B0%D0%BA-%D1%81%D0%BE%D1%85%D1%80%D0%B0%D0%BD%D0%B8%D1%82%D1%8C-%D0%B7%D0%BD%D0%B0%D1%87%D0%B5%D0%BD%D0%B8%D0%B5-%D0%BF%D0%B5%D1%80%D0%B5%D0%BC%D0%B5%D0%BD%D0%BD%D0%BE%D0%B9-%D1%87%D0%B5%D1%80%D0%B5%D0%B7-session

https://qna.habr.com/q/1171888

https://www.php.net/manual/ru/book.session.php

https://ru.eitca.org/%D0%B2%D0%B5%D0%B1-%D1%80%D0%B0%D0%B7%D1%80%D0%B0%D0%B1%D0%BE%D1%82%D0%BA%D0%B8/eitc-wd-pmsf-%D0%BE%D1%81%D0%BD%D0%BE%D0%B2%D1%8B-php-%D0%B8-mysql/%D1%8D%D0%BA%D1%81%D0%BF%D0%B5%D1%80%D1%82%D0%B8%D0%B7%D0%B0-%D0%B2-php/%D1%81%D0%B5%D1%81%D1%81%D0%B8%D1%8F%D1%85/%D0%BE%D0%B1%D0%B7%D0%BE%D1%80%D0%BD%D1%8B%D0%B5-%D1%8D%D0%BA%D0%B7%D0%B0%D0%BC%D0%B5%D0%BD%D0%B0%D1%86%D0%B8%D0%BE%D0%BD%D0%BD%D1%8B%D0%B5-%D1%81%D0%B5%D1%81%D1%81%D0%B8%D0%B8/%D0%BA%D0%B0%D0%BA-%D0%BC%D1%8B-%D0%BC%D0%BE%D0%B6%D0%B5%D0%BC-%D1%81%D0%BE%D1%85%D1%80%D0%B0%D0%BD%D0%B8%D1%82%D1%8C-%D0%B7%D0%BD%D0%B0%D1%87%D0%B5%D0%BD%D0%B8%D0%B5-%D0%B2-%D0%BF%D0%B5%D1%80%D0%B5%D0%BC%D0%B5%D0%BD%D0%BD%D0%BE%D0%B9-%D1%81%D0%B5%D0%B0%D0%BD%D1%81%D0%B0/

https://rwsite.ru/sessii-v-php/

https://code.tutsplus.com/ru/how-to-use-sessions-and-session-variables-in-php--cms-31839t

https://antonshevchuk.gitbooks.io/php-for-beginners/30_authorization/session.html

https://symfony.ru/doc/current/components/http_foundation/session_configuration.html