"Costless" refers to something that does not incur any expense or financial charge. It can apply to various contexts, such as services, products, or experiences that are provided for free. For example, many online platforms offer free trials or open-source software that users can access without payment. In economics, the term can also describe situations where the opportunity cost is negligible. This means that engaging in a particular activity does not require sacrificing other valuable resources. Understanding the concept of costlessness can help individuals and businesses make informed decisions about resource allocation and investment.