CIPA stands for Camera & Imaging Products Association.
This Japan-based organization is composed of photography professionals engaged in the production of digital and film cameras. They release a rating for each camera called the battery life CIPA, or simply CIPA, which refers to the number of images a digital still camera can take on a single battery charge.
A Sony digital camera such as the Sony a7S III yields a battery life CIPA of 510 shots when using the viewfinder and approximately 600 when using the LCD monitor. For comparison, a Fujifilm digital camera such as the Fujifilm X-T4 has a battery life CIPA of about 500 shots, close to the average of 411.
However, this rating depends on the type of camera you’re testing. To gauge the CIPA battery life of a camera, the organization uses it to take photos every 30 seconds. They leave the camera on between every image, turn it off after every ten shots, and repeat it.
As this is not how people use digital cameras, the actual battery life you'll get from a single charge will vary. The way you shoot and the settings you choose have a considerable impact on battery life. For example, if you're shooting without the LCD screen enabled or in manual focus mode, you could expect a greater amount of shots than the CIPA rating.