A power bank is a portable device that stores electrical energy for charging electronic gadgets like smartphones, tablets, and cameras. It typically contains a rechargeable battery and has one or more USB ports for connecting devices. Power banks come in various sizes and capacities, allowing users to choose one that best fits their needs for on-the-go charging. These devices are especially useful during travel, outdoor activities, or emergencies when access to a power outlet is limited. Many power banks also feature fast charging technology and LED indicators to show the remaining battery life. They have become essential accessories for anyone reliant on their smartphones and other portable electronics.