こんにちは Today we're going to be
talking about HTML5. Specifically what it is, and
why we aren't learning HTML1 instead. So what is HTML? HTML stands for hypertext markup language. Markup languages are actually very common. They're not the same as
programing languages, instead they're special languages that
use tags to annotate or markup documents. In HTML, the tags tell the browsers
where you want to put headings, images, lists, links, et cetera. A .HTML file is a special kind of file. You've already seen special
file extensions before. Whenever you open a file that has a .doc, your computer knows to
open it in Microsoft Word. If you see a file with
.ppt your computer knows, oh that's a Power Point file,
I should open it in Power Point. In the same way, when you computer sees
the .html file, it knows that it should open it in an internet browser
such as Chrome, Firefox or Safari. Your browser can read this file and
it knows how to display it on the screen. It's more than that, HTML file tags also
allow screen readers and other assisted devices to utilize the tags to present
the information in new and special ways. So HTML is very similar to English, you can understand it even if
you don't know much about it. Let's look at this example
HTML file over here. Most of it is just
a typical English language. This is an important heading or hi there. I am going to include
a link to the course page. But if you look closely, you can see
we've added these little tiny tags that the browser use this to know
how to represent the material. So, h1 is just the heading tag. It says to the browser,
hey this is something really important. I want you to put it in bigger font, and
also if someone is using an assisted device, I want them to know if
this is something important. H2 also displays some sort of importance,
but not as much. I have a p tag for a paragraph, and I have another tag down
here called and anchor tag. To let the browser know, I don't
want you to just show this material, I want you to actually link
it to a different web page. So here's the output when any
browser would look at our code. In the beginning, learning HTML is mostly
about learning all those different tags that I showed you in that file. This is called learning the syntax. It's how you learn which brackets to use,
backslashes, and different things like that. You spend most of your time going,
oh, did I remember that tag and did I write it the right way? That's very short-lived. In just a little amount of time, you're gonna gain the confidence
to not worry about your syntax and instead to be thinking about the semantics
or the meaning behind the tags. How important is this information
that I'm trying to get across, and is this the right tag to be using? If someone's searching my page,
can they find what they're looking for? Even if they can't see the text, can they
use the tags to navigate through it? So what happened to HTML1? Why are we using something called HTML5? Well, let's talk about the early years. HTML was created in 1990 as
a way to electronically connect different documents via hyperlinks. Hence, this idea of a web of connections. What was happening, is that scientists were using the Internet
to list their different research papers, and you would have a long list,
each paper independent of the other. But, HTML, gave you ways that
you could read a paper, and right within the text,
link to another exciting physics paper. Because the audience from HTML tended
to be people like my dad up there in the corner, they were nuclear physicists,
they didn't care about things such as color, images, or anything that wasn't
science related, and that was the key. HTML was intended to
work across any platform. And in order to do this you really had
to avoid things such as special fonts or different colors or anything that
was more about layout than content. However, in 1993 Mosaic emerged
as the first graphical browser. And what that means is that there was
a first browser to actually introduce the idea of images and
when that happened, there was a lot of debate among the research community as
to whether or not this was a good thing. The pioneers really wanted to
keep it simple content based, let everyone access it. But the innovators were saying no. People like pictures, they like layout. They like that even as much
as they like the content. So there is a big battle between how the
Internet should evolve from that point. So after Mosaic emerged, the use of
the Internet just absolutely exploded, and more and more people were using it for
commercial means, instead of just for doing research. Mosaic had challengers though, in the form
of Netscape, Internet Explorer and other browsers. This was the start of what
we call the browser wars. Each of these browsers decided that they
wanted to create these proprietary tags, tags that would only
work on their browser. Some of the examples were marquee,
where you could have scrolling text, or blink which would only work on some
of the browsers and not others. Other tags were proprietary,
they actually worked on any browser, but they went against
the original spirit of HTML. They were tags such as font or center, for
centering your text or background color. This may not sound like a bad thing, but some computers didn't have the access,
didn't have the ability to have all the different colors
that other computers might have. And this led to some
really ugly looking pages. That also led to the origination of what
we call the best viewed on messages. When you went to a site you
almost immediately told which browser you should
really view the site on. Otherwise, you weren't going
to get the optimal experience. We all in a way suffer from browser wars,
or best viewed on images today. Many times when you go to a page, you'll see that you can't actually access
the full content if you're on your phone, unless you click on a link
to the full website. So how did this happen? How did we get to the point where
different browsers weren't agreeing on the different roles
that HTML should play? This comes back to the idea that no
one runs the Internet or the Web. However, some groups have
taken a more proactive role to try to help standardize
what's going on out there. The first is
the Internet Engineering Task Force, they really focus on the idea of how the
different networks should collaborate and how they should work together. The World Wide Web Consortium, instead
deals with HTML and the evolution of HTML, they want to know what kinds of tags the
browsers should and should not support. Finally, one of the newest groups,
The Web Accessibility Initiative, they want to make sure, that no matter
how people are accessing the web, they have the same ability
to view the content. We had this evolution of browsers
that we've been talking about. In 1990 to '94 it was all very simple,
text-based. In '93, we talked about how
the images entered the scene, and pretty much exploded the Internet. Cross-browser compatibility made many
of the web pages just fall apart and led to incredibly ugly code. In the beginning of 2000 browsers went
back to this idea of separating content from style. And in 2005 it became standard practice
to use HTML files, which we are learning about in this course, to create
the content and CSS files to style it. So as the browsers evolved so did HTML. The way it tends to work
in most computer signs and technology fields is that it's the coders
and the developers who push the standards. So as coders learned that there more and more things that they wanted the ability
to do, it's the browsers job to keep up. So, where are we now? HTML5 is a cooperation between W3C and the Web Hypertext Application
Technology Working Group, and what they've done is they've
established these four guidelines for how HTML5 should be approached
as browsers go to support it. The first idea is that new
features should be based on HTML, CSS which is the sign language,
the DOM and JavaScript. Nothing more. They want to reduce the need for external
plug-ins, it's very frustrating when you're on a browser and you find that you
can't watch the video that someone posted. They also want to move so that mark up, or the mark up language
can replace scripting. If you find that more and more developers
are writing code to make something happen, get rid of the code and just make
a simple tag that can do it instead. And finally,
HTML5 should be device independent. It shouldn't matter whether you're
on your phone, you laptop, a PC or even on a screen reader. You want everyone the same
access to the information. So when you think back over this video, there are certain lessons I
really hope to stick with you. The first is the idea that HTML
is not a programing language, but rather a way that browsers can translate
documents into viewable webpages. HTML was intended to facilitate
many different content types. Images, pictures, links, lists. Every thing along that line. What we've found thought
the history of the Internet, is that when designers want to
do something They tend to write nonstandard code to
force browsers to do it. So, this is why we're developing new
standards in HTML5 to handle these new requirements that people desire and
push browsers to adopt the new standards.