Symbian is a mobile operating system originally developed for smartphones. It was created in the late 1990s and became popular for its ability to support various applications and features, making it a preferred choice for many manufacturers, including Nokia and Sony Ericsson. The platform was known for its multitasking capabilities and user-friendly interface. However, as the smartphone market evolved with the rise of iOS and Android, Symbian struggled to keep up and eventually lost its dominance, leading to its decline in the early 2010s.