What is the use of the view.xml of theme etc directory in magento 2?

In Magento 2, the view.xml file is used to define and configure image properties such as sizes, aspect ratios, and image types for a theme. This file is located in the etc directory of a theme (app/design/frontend/{Vendor}/{theme}/etc/view.xml) and plays an important role in controlling how images are displayed across different parts of the store (e.g., product listing pages, product detail pages, category pages, etc.).

Key Purposes of view.xml in Magento 2:

1. Image Dimensions: The view.xml file allows you to define the width and height of various image types (e.g., product thumbnails, small images, etc.) for both product listings and detail pages.
2. Image Aspect Ratios: You can maintain a specific aspect ratio for images to ensure they look consistent across the site.
3. Responsive Images: The file helps ensure images are properly optimized and resized for different screen sizes (desktop, mobile, etc.).
4. Image Placeholder Settings: You can specify placeholder images that are displayed when a product image is not available.

Structure of view.xml:

Here’s an example of a typical view.xml configuration:

<view xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Config/etc/view.xsd">
    <media>
        <images module="Magento_Catalog">
            <image id="category_page_grid" type="thumbnail">
                <width>240</width>
                <height>300</height>
            </image>
            <image id="product_page_main" type="image">
                <width>700</width>
                <height>560</height>
            </image>
            <image id="cart_page_product_thumbnail" type="small_image">
                <width>75</width>
                <height>90</height>
            </image>
        </images>
    </media>
</view>

Common Use Cases:

1. Customizing Image Sizes: If a theme requires different image dimensions than the default, you can modify the image sizes in view.xml to match the design.
2. Improving Performance: By specifying different image sizes for desktop and mobile views, you can ensure the site loads optimized images, improving performance on different devices.