How do I pass a dynamic PHP variable from one page to another?

I am creating 2 webpages. The first one will show a list of items. 2nd web page, I want to create a general one so that when the user clicks on an item depending upon the chosen one, 2nd page will be modified as per item. I just want to pass a string variable from which I can obtain rest of the the things from database. Just like an e-commerce website.

There are a couple of ways to achieve what you want.

Some examples:

Using GET:

You can use a link to pass a variable to the next page.

Page 1:

<a href="yourpage2.php?variable=<?php echo $value; ?>">Page 2</a>

Page 2:

if(isset($_GET['variable'])) {
    $new_variable = $_GET['variable'];
}

Using POST:

Page 1:

<form method="POST" action="yourpage2.php">
    <input type="hidden" name="variable" value="<?php echo $value; ?>">
    <input type="submit" value = "Next Page">
</form>

Page 2:

if(isset($_POST['variable'])) {
   $new_variable = $_POST['variable'];
}

Using COOKIE:

Page1:

$_COOKIE['variable'] = $value;

Page 2:

$new_variable = $_COOKIE['varname'];

When using cookies, the variable's value is stored on the client side, opposite of sessions, where the value is stored on the server side.

Using SESSION:

Page 1:

$_SESSION['variable'] = $value;

Page 2:

$new_variable = $_SESSION['variable'];

Notice: When using SESSIONS, do not forget to include/write session_start(); in the start of your page right after your <?php tag on BOTH of your pages.