Why are alt tags important for images in SEO?

Alt tags are important for images in SEO primarily because they provide context for search engines and improve accessibility. When search engines crawl a website, they rely on various signals to understand the content. Alt tags serve as a descriptive text alternative for images, allowing search engines to index the visual content effectively. This means that if a search engine can't "see" the image, it can still understand what it is about through the alt text, which helps in ranking the content appropriately.

Additionally, alt tags play a pivotal role in accessibility for visually impaired users who rely on screen readers to understand the content of a webpage. Screen readers read out the alt text, allowing users to grasp the context of images, thereby enhancing their experience on the website. Using descriptive and relevant alt tags not only aids in improving search engine visibility but also ensures inclusivity for all users.

The other choices do not accurately align with the primary functions of alt tags in the context of SEO. For instance, while optimizing loading speed or aesthetics might contribute to a better user experience, they are not directly related to the use of alt tags. Therefore, the importance of alt tags lies in their ability to enhance search engine understanding and accessibility.