As your web projects grow larger and more complicated, you will find
an increasing need to keep track of your users. Even if you aren’t offering
logins and passwords, you will still often need to store details about a
user’s current session and possibly also recognize people when they return
to your site.
Several technologies support this kind of interaction, ranging from
simple browser cookies to session handling and HTTP authentication. Between
them, they offer the opportunity for you to configure your site to your
users’ preferences and ensure a smooth and enjoyable transition through
Using Cookies in PHP
A cookie is an item of data that a web server saves to your computer’s hard disk
via a web browser. It can contain almost any alphanumeric information (as
long as it’s under 4 KB) and can be retrieved from your computer and
returned to the server. Common uses include session tracking, maintaining
data across multiple visits, holding shopping cart contents, storing login
details, and more.
Because of their privacy implications, cookies can be read only from
the issuing domain. In other words, if a cookie is issued by, for example,
oreilly.com, it can
be retrieved only by a web server using that domain. This prevents other
websites from gaining access to details for which they are not
Due to the way the Internet works, multiple elements on a web page can be embedded from multiple domains, each of which can issue its ...
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