Because of the unique nature of objects, they cannot be as easily managed as strings or numbers. This makes them more difficult to store in a database, pass along to a second PHP script, or set as a cookie. To handle such issues, PHP has the serialize() function, which takes a variable and turns it into a more manageable version of itself. It works like so:
$variable = serialize ($object);
To return the serialized variable back into its standard form, use the unserialize() function.
$object = unserialize ($variable);
The only caveat to using these two functions with objects is that the page that unserializes the variable must have access to the class definitions.
As a crude analogy, say you had created a really cool toy ...