A category page that's just a grid of products, with nothing else on it, often qualifies as thin content in the eyes of a search engine trying to judge how genuinely useful a page is. This is one of the most common, most fixable gaps across ecommerce sites of every size.
What "thin content" actually means here
It's not about word count for its own sake. A category page with a bare product grid gives a search engine, and a human visitor, nothing to work with beyond the products themselves. There's no context, no guidance, nothing helping someone decide between the options in front of them.
What a genuinely useful category page includes
A short amount of real content, explaining what the category covers, what to look for when choosing, or answering a common question, gives both search engines and visitors something substantive. This doesn't need to be long. A few well-written paragraphs, placed above or below the product grid, consistently outperforms either nothing or an overstuffed wall of text written purely to hit a word count.
Where to place the content
Above the grid works well for broader, more exploratory categories where context genuinely helps before someone starts browsing. Below the grid works well for more specific categories where people generally know roughly what they want and just need to start comparing options.
Don't create thin content by over-splitting categories
The opposite problem also happens: categories split so finely that none of them have enough products or content to be genuinely useful. A category with three products and no content is thin regardless of how narrowly it's defined.