Okay, here’s a breakdown of the HTML code snippet you provided, focusing on the image and its surrounding elements. I’ll explain what each part does and what it means in terms of how the image is displayed.
Overall structure
The code is a section of HTML likely representing a “teaser” or preview of an article or content piece. It includes an image and some surrounding text. The key element here is the <picture> tag, which is used for responsive images.
1. <picture> Tag
* <picture>: This tag is the core of the responsive image setup. It allows the browser to choose the most appropriate image source based on the screen size and other factors.
2. <source> Tags
* <source type="image/webp" media="(max-width: 40em)" srcset="...">: these tags define different image sources.
* type="image/webp": Specifies that the image is in WebP format (a modern image format that offers better compression and quality than JPEG or PNG).
* media="(max-width: 40em)": This is a media query. It means that this <source> tag applies only when the screen width is 40em or less. (1em is typically equal to the current font size, so 40em is roughly 640 pixels if the default font size is 16px).
* srcset="...": This attribute lists the different image URLs available for this media query. Each URL is followed by its width in pixels (e.g., https://.../weihnachtsmarkt-556.webp?width=256 256w).The browser will choose the most appropriate image from this list based on the screen resolution and pixel density.
* There are two sets of <source> tags:
* the first set uses the 16x9-big aspect ratio.
* the second set uses the 4x3 aspect ratio.
* The browser will choose the first matching <source> tag based on the media query.
3. <img> Tag
* <img src="..." alt="..." title="..." class="responsive" loading="lazy"/>: This is the fallback image. If the browser doesn’t support the <picture> tag or WebP format, it will display this image.
* src="https://images.ndr.de/image/61b097bd-1663-4914-b9ff-d3a4ed7b53cd/AAABmyf6ufY/AAABmyZE0EA/16x9-big/weihnachtsmarkt-556.webp?width=576": The URL of the image to display.
* alt="Two red mulled wine cups with a Christmas print.": Alternative text for the image (significant for accessibility). This is displayed if the image cannot be loaded.
* title="Two red mulled wine cups with a Christmas print. | picture alliance, Maximilian Koch": The title attribute, which appears as a tooltip when the user hovers over the image.
* class="responsive": A CSS class that likely applies styles to make the image responsive (e.g., max-width: 100%; height: auto;).
* loading="lazy": This attribute tells the browser to lazy-load the image, meaning it won’t be loaded until it’s near the viewport (visible area of the screen). This improves page load performance.
4. Surrounding <div>s
* <div> with class="teaserpadding": Adds padding around the teaser content.
* <div> with class="teasertext": Contains the text associated with the teaser (which is not included in your snippet).
How it Works (Responsive Images)
- Browser Checks: The browser looks at the
<picture>tag and its<source>
