Mortar shells are explosive projectiles designed to be fired from a device called a mortar. They are typically used in military operations to deliver indirect fire against enemy positions. Mortar shells come in various sizes and types, including high-explosive, smoke, and illumination shells, each serving a specific purpose on the battlefield. When a mortar shell is fired, it travels in a high-arcing trajectory before detonating upon impact or at a predetermined altitude. This allows for effective targeting of areas that are not directly visible to the shooter. Mortar systems are valued for their portability and ability to provide support in various combat situations.