PHP is one of the most popular scripting languages for use on the web. Now in version 4, its
phenomonal growth has come mostly at the expense of Perl and CGI.
It's open-source, easy-to-learn for Perl programmers, and is rapidly
expanding beyond only web use, making it a good language to learn.
The oldest web interaction technology, and no longer 'hot and sexy',
this trusty old workhorse nevertheless remains indespensible.
Although still not standardised (and doing very well in spite of it),
this server-side technology works well on virtually all platforms.
BTW this is a topic that the W3C has never been very keen on;
I've heard from key W3C people that they wished CGI would go away.
And one day perhaps it will, but not this year, nor the next..
You can use HTML
to create interactive pages using
forms,
communicating with the server via the
Common Gateway Interface
(CGI) - a standard for external gateway programs to interface with
information servers, such as
HTTP or Web servers.
A plain HTML document that the Web server delivers is static,
which means it doesn't change.
A CGI program, on the other hand, is executed in real-time, so that it
can output dynamic information - perhaps a weather reading, or the
latest results from a database query.
JavaScript is NOT JAVA !
JavaScript is NOT JAVA !
JavaScript is NOT JAVA !
...I had to get that out of the way; so many people either believe
these are the same technologies, or are just plain sloppy. Either way,
the error leads to false information. They are quite different.
JavaScript is a lightweight client-only scripting language,
suitable for calculators and other relatively non-GUI gizmos.
In particular, you'll need it for
Dynamic HTML.
A client-side technology, essential for effective dynamic pages;
problematic due to differences between the major browsers..
If you are impressed with sites where images slide around then you need
DHTML; but be aware that The Big Two do things differently.
My recommendation: study the standards and work first on the browser
that comes closest..
"Dynamic HTML" is typically used to describe the combination of
HTML,
style sheets and
scripts
that allows a web page to change after it's loaded into the
browser --there doesn't have to be any communication with the web
server for an update. You can think of it as 'animated' HTML.
For example, a piece of text can change from one size or color to
another, or a graphic can move from one location to another,
in response to some kind of user action, such as clicking a button.
Graphics spice up a web site,
and with
GIF animation can be made more
eye-catching (or distracting, and certainly larger). But there are
many more options, allowing interesting audio and visual effects,
e.g
Shockwave,
Java,
etc.
Much-hyped for a long time now, this language holds great promise,
perhaps more for locations other than browsers, where it tends to be too
slow (to load) for the more impatient among us.
Java (tm) is a simple, robust, dynamic, multi-threaded,
general-purpose, object-oriented, platform-independent
programming environment, created and developed by Sun Microsystems.
Developers can write custom mini-applications called applets,
which will provide Internet sites with a huge range of new
functionality: animation, live updating, two-way interaction, and more.
When integrated into Web pages, Java applets allow expert graphics
rendering, real-time interaction with users, live information updating,
and instant interaction with servers over the network. Java applets are
downloadable from any server and run safely on any platform.
Java applets allow cross-platform programmability and can be embedded
right into HTML pages.
The power of the WWW
comes not simply from static
HTML pages - which can be very
attractive, and the important first step into the WWW -
but especially from the ability to support those pages
with powerful
software,
especially when interfacing to databases.
The combination of attractive screen displays,
exceptionally easy to use controls and
navigational aids,
and powerful underlying software,
has opened up the potential for people everywhere to tap
into the vast global information resources of the
Internet.
