An alarm clock is a device designed to wake people up or remind them of something at a specific time. They come in a variety of shapes and sizes, and work with different mechanisms, such as traditional hands or modern digital displays. Some alarm clocks rely on loud ringtones, while others use vibrations or glowing lights. Modern alarm clocks come with advanced options, such as the ability to set custom ringtones, connect them to smartphones, and even simulate the sunrise to gently wake the user. There are also alarm clocks that have a snooze feature to provide a short extra period of sleep before they ring again. There are alarm clocks that use natural sounds, such as chirping birds or the sound of running water, to help people wake up peacefully. Some are designed in an innovative way, such as flying alarm clocks that force the user to get up to look for them and turn them off. Alarm clocks are used not only to wake up in the morning, but also to remind people of important appointments or as a time organizer while working or studying. In the modern era, smartphone apps have come to offer similar functions, making using an alarm clock easier and more flexible. Regardless of its type, an alarm clock remains an essential tool in most people's lives, helping them organize their time and achieve their daily goals efficiently.