What is the difference between src and href

Src and href have different uses, different tags, different loading methods, different impacts on documents, and different optionalities. Detailed introduction: 1. src is used to specify the address of external resources, and href is used to specify the address of the target resource of the hyperlink; 2. src is usually used for img tags, script tags, audio tags, video tags, etc., and href attributes are usually used for a tag, link tag, @import directive, etc.; 3. The resource pointed to by the src attribute will be immediately loaded and parsed by the browser, etc.

# Operating system for this tutorial: Windows 10 system, Dell G3 computer.

src and href are two commonly used attributes used to reference external resources in HTML and XML documents. Although they do similar things, there are some differences in usage and functionality.

Different purposes:

The src (source) attribute is used to specify the address of external resources, usually used to introduce script files, image files, audio files, video files, etc. It tells the browser to embed external resources within the current document.

href (hypertext reference) attribute is used to specify the address of the target resource of the hyperlink. It is usually used to link to other HTML documents, style sheets, font files, ICO files, etc.

The tags targeted are different:

The src attribute is usually used for img tags, script tags, audio tags, video tags, etc., to introduce corresponding resources.

The href attribute is usually used in a tags, link tags and @import instructions, etc., to create links.

Different loading methods:

The resource pointed to by the src attribute will be loaded and parsed immediately by the browser. During the loading process, the browser will pause the loading of other resources and the rendering of documents until the resource is downloaded and executed.

The resource pointed to by the href attribute is loaded asynchronously when the document is loaded and will not block the rendering of the document. The browser loads multiple resources in parallel and continues to render the document.

Differences in impact on documents:

The src attribute has a direct impact on the structure and content of the document. For example, the image resource specified by the src attribute of the img tag will occupy the corresponding position in the document.

The href attribute has no direct impact on the structure and content of the document. For example, the style sheet specified by the href attribute of the link tag will change the style of the document through CSS rules.

Different optionality:

The src attribute is required. If the src attribute is not specified, the browser will consider the tag to be invalid.

The href attribute is optional. If the href attribute is not specified, the tag is still valid.

In summary, src is mainly used to specify the address of external resources to be embedded, while href is mainly used to create hyperlinks to the addresses of other resources. src loads resources immediately and affects the document structure and content, while href loads resources asynchronously and has no direct impact on the document structure and content. Understanding the differences between src and href is important to using them correctly and optimizing web page performance.

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