It’s a model that was built with a way smaller budget and uses less computing resources than OpenAI’s models. It’s also open sourced (you can run it locally; or improvise it to your needs) unlike OpenAI’s models.

The way AI usage is typically sold so it could be integrated to other tools is that you pay as much as you use. Deepseek’s models significantly undercuts OpenAI’s models in pricing while offering similar performance.