PHP comes with a Web framework built in (that's what things like `$_GET`, `$_POST`, `htmlentities`, etc. are). It is also a templating language, that's why we n

PHP comes with a Web framework built in (that's what things like `$_GET`, `$_POST`, `htmlentities`, etc. are). It is also a templating language, that's why we need to write `<?` at the start (to open a PHP tag).