The article discusses embeddings, a technique used in natural language processing and machine learning to represent content as arrays of floating point numbers. This allows for the calculation of semantic similarities between pieces of content, enabling applications such as related content search and semantic search. The article explains how embeddings work and provides examples of their use, including a project that used embeddings to build a related content feature for a blog. The article also touches on the use of openly licensed models and the potential risks of relying on proprietary models.