A URL (Uniform Resource Locator) is the complete address used to locate a specific resource on the internet, such as a webpage, image, or video. The src attribute in HTML, short for "source," is used to embed a resource, often a URL, directly into a document.
What is a URL (Uniform Resource Locator)?
A URL is essentially the address of a resource on the World Wide Web. It provides a way to identify and locate anything accessible over the internet, acting like a street address for web content.
Components of a URL
A typical URL is structured into several parts that help a browser find and access the desired resource:
- Protocol: Specifies how the browser should retrieve the resource (e.g.,
http://,https://,ftp://).HTTPS(Hypertext Transfer Protocol Secure) is the most common and secure protocol for web pages. - Domain Name: The human-readable name of the server hosting the resource (e.g.,
www.example.com). - Path: The specific location of the resource within the server's file system (e.g.,
/images/logo.png). - Query Parameters (optional): Information passed to the server, often for dynamic content (e.g.,
?category=news). - Fragment Identifier (optional): Points to a specific section within the resource (e.g.,
#section-title).
Example:
https://www.example.com/products/item?id=123#description
Here, https is the protocol, www.example.com is the domain, /products/item is the path, ?id=123 is a query parameter, and #description is a fragment identifier.
URLs are fundamental for navigation and accessing web content, often utilized in HTML through attributes like href (Hypertext Reference) to create hyperlinks.
What is the src Attribute?
The src attribute (short for "source") is an essential HTML attribute used to specify the location (URL) of an external resource that needs to be embedded directly into the current document. When a browser encounters an src attribute, it fetches that resource and inserts it into the webpage at that point.
Common Uses of the src Attribute
The src attribute is vital for elements that display or execute external content as part of the page's structure or functionality:
<img>(Image): Specifies the path to an image file.- Example:
<img src="[https://www.example.com/images/logo.png](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img)" alt="Company Logo">
- Example:
<script>(JavaScript): Links to an external JavaScript file for dynamic functionality.- Example:
<script src="[https://www.example.com/js/main.js](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script)"></script>
- Example:
<video>and<audio>(Multimedia): Points to video or audio files.- Example:
<video controls src="[https://www.example.com/media/clip.mp4](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/video)"></video>
- Example:
<iframe>(Inline Frame): Embeds another HTML document within the current one.- Example:
<iframe src="[https://www.example.com/embedded-page.html](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe)"></iframe>
- Example:
src vs. href: Understanding the Difference
While both src and href attributes reference URLs, their fundamental purpose and how the browser handles them are distinct. This distinction is crucial for proper web development.
The href attribute specifies the location (URL) of a resource that an anchor element (<a>) points to, or the location of a linked resource, like a stylesheet (<link>). It establishes a link or reference to another resource that the user or browser can navigate to. The browser typically does not embed or execute the href resource directly into the current page content.
In contrast, the src attribute is used to embed a resource directly into a document. The browser fetches the resource specified by src and then directly inserts it as part of the current page's content, whether it's an image, a script, or multimedia.
Key Differences Summarized
| Feature | src Attribute (Source) |
href Attribute (Hypertext Reference) |
|---|---|---|
| Purpose | Embeds a resource directly into the current document. | Links or refers to another resource. |
| Browser Action | Fetches and inserts the resource into the page. | Points to a resource; typically navigates to it or applies it. |
| Common Elements | <img>, <script>, <video>, <audio>, <iframe> |
<a> (for hyperlinks), <link> (for stylesheets) |
| Resource Type | Content that becomes part of the page's display/function. | Navigable links, external stylesheets, page anchors. |
| Loading | Content usually loaded and rendered as part of the page. | Can be loaded on user interaction (click) or in parallel. |
For example, an <img> tag with src displays an image on the page, while an <a> tag with href creates a clickable link that takes the user to a new page or section. Understanding this distinction is vital for optimizing page performance and structure.
