What is the purpose of the alt attribute in HTML?

The alt attribute in HTML serves the purpose of providing alternative text for images. This is essential for several reasons. Primarily, it ensures accessibility for visually impaired users who rely on screen readers to interpret web content. When an image cannot be displayed or loaded, the alt attribute's text appears in its place, conveying the image's meaning or intended function.

Additionally, the alt attribute can improve search engine optimization (SEO) by helping search engines understand the content context of the images on a page. Proper use of alt text can enhance user experience and website navigability, making it a critical aspect of web development.

The other choices relate to functionalities that do not involve the alt attribute’s primary role. Aligning, styling, or linking images does not pertain to the purpose of the alt attribute, which is solely focused on providing descriptive text.