An SEO glossary of terms every marketer should know in 2026
A practical, current glossary covering the essential SEO terminology every marketer should be comfortable with, from foundational concepts to 2026-specific terms.
6 min read
Image search remains an underused traffic source for many businesses, particularly in categories like fashion, food, home decor and product photography, where visual search behaviour is common. Proper image optimisation also directly supports accessibility, and increasingly, multimodal AI understanding of your content.
File naming
Descriptive, hyphenated file names ('blue-cotton-summer-dress.jpg' rather than 'IMG_4821.jpg') give Google an additional, if modest, signal about the image's content before it even analyses the visual data itself.
Alt text: the highest-value element
Alt text serves both accessibility (screen readers rely on it) and SEO purposes simultaneously. It should genuinely describe what the image shows, concisely and naturally, without keyword stuffing — 'a woman wearing a blue cotton summer dress standing on a beach' rather than just 'blue dress summer dress cotton dress beach dress'.
- Describe what the image genuinely shows, in natural language.
- Keep it concise — typically under 125 characters for optimal screen reader experience.
- Avoid keyword stuffing, which harms both accessibility and search credibility.
- Leave alt text empty (not omitted) for purely decorative images with no informational content.
Good alt text serves a blind screen reader user and a search engine's understanding of your page with the exact same sentence — there is no tension between accessibility and SEO here, only alignment.
Technical image optimisation
Compress images appropriately, serve modern formats like WebP where supported, and use responsive images (srcset) to serve appropriately sized files for different screen sizes — this affects both Core Web Vitals scores and image search eligibility, since very large or slow-loading images can be deprioritised.
Structured data for images
ImageObject schema, and product-specific schema that references images, can improve eligibility for certain rich results and gives search engines additional structured context beyond alt text alone.
Sitemaps for images
For image-heavy sites, an image sitemap (or image entries within your existing XML sitemap) can help ensure Google discovers and indexes images that might otherwise be missed, particularly those loaded via JavaScript or lazy loading. Google's image SEO documentation is the authoritative technical reference.
Frequently asked questions
Does image alt text affect ranking for the page's main text content?
Not directly for the page's primary text ranking, but it contributes to the overall relevance and accessibility signals for the page, and specifically affects image search visibility.
Should every image have alt text?
Every genuinely informative image should. Purely decorative images (background textures, dividers) should have empty alt attributes (alt="") rather than omitting the attribute entirely, which is the correct accessibility practice.
Is image search traffic worth optimising for?
For visually-driven categories — fashion, food, home decor, travel — yes, image search can be a meaningful, often underused traffic source worth the relatively low effort required to optimise for it properly.
If your product or content images are not optimised for search, reach out to our team for a review.
The takeaway
Rewrite your alt text to genuinely describe what each image shows, not to stuff a keyword — this single habit improves both accessibility and search performance at once.
Written by Fibvo — Bengaluru and Erode, India — working with clients in other time zones. Questions, or think we have it wrong? Tell us.
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