LSI keywords, or latent semantic indexing keywords, are an essential part of modern search engine optimisation (SEO). These terms go beyond simple keywords by focussing on the relationships between different words and concepts. They help search engines to better understand the context and content depth of a text.

The use of LSI keywords can significantly improve the visibility of a website in search engine results. Instead of focussing on a single word, these semantically related keywords take into account a wider range of terms related to the main topic. This enables search engines such as Google to assess the relevance and quality of a piece of content more precisely.

Example: If writing an article on "healthy eating", LSI keywords would not only be "health" or "nutrition", but also related terms such as "balanced diet", "nutrients", "physical well-being" and "food". These additional keywords expand the topic and provide a broader context.

However, it should be noted that the use of LSI keywords should be natural and sensible. An excessive or inappropriate accumulation of these terms can have a negative effect and be recognised by search engines as "keyword stuffing". Instead, these terms should be embedded organically in the text to increase readability and relevance.

To summarise, LSI keywords play an important role in SEO strategy. Not only do they help to convey the context and breadth of a piece of content, but they also improve the user experience by ensuring that content is relevant to search queries. Ultimately, this leads to higher rankings in search results and increased visibility on the web.