S40 smartphones are a category of mobile devices that run on the Nokia Series 40 operating system. These phones are designed for basic functionality, offering features like calling, texting, and simple applications. They are often more affordable than smartphones running on advanced operating systems, making them accessible to a wider audience. Typically, S40 smartphones come with a user-friendly interface and a variety of pre-installed apps, including social media and games. While they lack the advanced capabilities of modern smartphones, they are suitable for users who prioritize essential communication and basic entertainment over high-end features.