The id Attribute

The HTML id attribute is used to specify a unique id for an HTML element (the value must be unique within the HTML document).
Using The id Attribute
The id attribute is used by CSS or JavaScript to perform certain tasks for the element with the specific id value.
In CSS, to select an element with a specific id, write a hash (#) character, followed by the id of the element:

HTML Iframes

An HTML iframe is used to display a web page within a web page. 0247024887

What is Multimedia?

Multimedia comes in many different formats. It can be almost anything you can hear or see, like images, music, sound, videos, records, films, animations, and more.
Web pages often contain multimedia elements of different types and formats.
Browser Support
The first web browsers had support for text only, limited to a single font in a single color.
Later came browsers with support for colors, fonts, images, and multimedia!
Multimedia Formats
Multimedia elements (like audio or video) are stored in media files.
The most common way to discover the type of a file, is to look at the file extension.
Multimedia files have formats and different extensions like: .wav, .mp3, .mp4, .mpg, .wmv, and .avi.
Common Video Formats
Videoformats There are many video formats out there.
The MP4, WebM, and Ogg formats are supported by HTML.
The MP4 format is recommended by YouTube.


What is HTML Web Storage?

With web storage, web applications can store data locally within the user browser.
Before HTML5, application data had to be stored in cookies, included in every server request. Web storage is more secure, and large amounts of data can be stored locally, without affecting website performance.
Unlike cookies, the storage limit is far larger (at least 5MB) and information is never transferred to the server.
Web storage is per origin (per domain and protocol). All pages, from one origin, can store and access the same data.


Bootstrap 4 uses a default font-size of 16px, and its line-height is 1.5.
The default font-family is "Helvetica Neue", Helvetica, Arial, sans-serif.
In addition, all p elements have margin-top: 0 and margin-bottom: 1rem (16px by default). 0247024887


Push notifications to your visitors with a toast, a lightweight and easily customizable alert message.


Related Content


Button group Group a series of buttons together on a single line with the button group, and super-power them with JavaScript.


Encoding (Character Sets) To display an HTML page correctly, a web browser must know which character set to use.
What is Character Encoding?
ASCII was the first character encoding standard (also called character set). ASCII defined 128 different alphanumeric characters that could be used on the internet: numbers (0-9), English letters (A-Z), and some special characters like ! $ + - ( ) @ .
ISO-8859-1 was the default character set for HTML 4. This character set supported 256 different character codes.
ANSI (Windows-1252) was the original Windows character set. ANSI is identical to ISO-8859-1, except that ANSI has 32 extra characters.
Because ANSI and ISO-8859-1 were so limited, HTML 4 also supported UTF-8.
UTF-8 (Unicode) covers almost all of the characters and symbols in the world.
The default character set for HTML5 is UTF-8.
The HTML charset Attribute
To display an HTML page correctly, a web browser must know the character set used in the page.


Responsive Images Responsive images are images that scale nicely to fit any browser size.
Using the width Property
If the CSS width property is set to 100%, the image will be responsive and scale up and down:
Notice that in the example above, the image can be scaled up to be larger than its original size. A better solution, in many cases, will be to use the max-width property instead.
Using the max-width Property If the max-width property is set to 100%, the image will scale down if it has to, but never scale up to be larger than its original size


Thinking in React React is, in our opinion, the premier way to build big, fast Web apps with JavaScript. It has scaled very well for us at Facebook and Instagram.
One of the many great parts of React is how it makes you think about apps as you build them. In this document, we’ll walk you through the thought process of building a searchable product data table using React.


Bootstrap Containers You learned from the previous chapter that Bootstrap requires a containing element to wrap site contents.
Containers are used to pad the content inside of them, and there are two container classes available:
The .container class provides a responsive fixed width container
The .container-fluid class provides a full width container, spanning the entire width of the viewport


HTML Versus XHTML XHTML is a stricter, more XML-based version of HTML.
What is XHTML?
XHTML stands for EXtensible HyperText Markup Language
XHTML is a stricter, more XML-based version of HTML
XHTML is HTML defined as an XML application
XHTML is supported by all major browsers
XML is a markup language where all documents must be marked up correctly (be "well-formed").
XHTML was developed to make HTML more extensible and flexible to work with other data formats (such as XML). In addition, browsers ignore errors in HTML pages, and try to display the website even if it has some errors in the markup. So XHTML comes with a much stricter error handling