A walled garden is a term used to describe an enclosed or restricted environment where access and activities are controlled by a single entity. In the context of technology, it refers to a closed system in which content, applications, and services are only available through a specific platform or provider. This means that users cannot freely choose from a wide range of options but rather have limited choices within the walled garden. The term is often used when discussing mobile phone operating systems, social media platforms, and other online ecosystems where access to certain features or services may be restricted unless you use their specific products or services.