About the difference between shortcut icon and icon code of web page favorite icon (reprint)_html/css_WEB-ITnose

What is the difference between shortcut icon and icon code. Let’s introduce the
statement one:
Statement 2
Note: Statement 1 Shortcut Icon is the Icon
that appears in front of the URL column. Question: Statement What is the role of the second icon? What is the difference from the first statement?
Guide
In the past, website designers and developers used a variety of methods to ensure that the favicon appeared. It is difficult to unambiguously guarantee that a favicon will be displayed on all computers, even using the same version of a browser.
Another limitation of the following code is that it associates the favicon with a specific HTML or XHTML document. To avoid this, the favicon.ico file should be placed in the root directory. Most browsers will automatically detect and use it.
It is recommended to include the following two lines of HTML code:
CODE:


However, only the first line is required, as the "shortcut icon" string will be recognized by most standards-compliant browsers as listing possible keywords ("shortcut" will be ignored and only "icon" will apply) ; and Internet Explorer will treat it as a separate name ("shortcut icon"). The result of this is that all browsers can understand this code. Adding the second line is only necessary if you want to provide another fallback image for new browsers (such as an animated GIF).
In HTML, the link element must be within the head element (between and

).
For XHTML, link must be ended with "/>" (or ">"), but cannot be ended with ">".
The href can, but does not have to, point to the location of /favicon.ico. It can point to any URL.
Images can generally use any image format supported by the browser.
.ico file format can generally be read by all browsers that can display favicons.
Set up the server to send the correct MIME identifier:
ICO file image/vnd.microsoft.icon (or image/x-icon for compatibility reasons. However it is better to use the IANA registered MIME types , as most major browsers now support it)
GIF file image/gif
PNG file image/png
Use appropriate resolution and color depth.
ICO: Includes multiple resolutions (the most commonly used are 16×16 and 32×32, Mac OS X sometimes uses 64×64 and 128×128) and bit depth (bits per pixel) (mostly 4, 8, 24 bpp, that is, 16, 256 and 16 million colors).
GIF: Use 16×16, 256 colors.
PNG: Use 16×16, 256 colors or 24 bits.
Note: When favicon.ico is placed in the document root directory, it will be found by some browsers that do not handle the link element, even if there is no link to it on your site.
Standardization
The Favicon function was first created by Microsoft, and Microsoft's Internet Explorer web browser will request favicon for every website. The link tag supported by Microsoft does not comply with the HTML recommendations of the World Wide Web Consortium (W3C, World Wide Web Consortium) [1], because: The
rel attribute must contain a list of link types separated by spaces, so a list containing two words The link type cannot be understood by standards-compliant browsers.
The ".ico" file type (a raster format used for icons on Microsoft Windows) did not have a registered MIME type and did not appear to be understood by most browsers at the time. However, in 2003, this format was registered with IANA and its MIME type was image/vnd.microsoft.icon, thus eliminating the first part of this problem.
Using reserved locations on websites is inconsistent with the Architecture of the World Wide Web and is considered link squatting or URI squatting.
Mozilla browser adds support for favicons through a method that complies with web standards. It takes rel="icon" and allows web designers to add favicons in any supported image format. For example . Later, most browsers added support for this feature since it would be used for all new content.