As a way of enabling users to take and store more photos on their devices, Apple introduced the HEIC format in 2017. It stands for High-Efficiency Image Container and generally takes up about half the space of an equivalent quality JPG file. The color quality is far superior as well. Despite these benefits though, HEIC is not recognized by other operating systems and a lot of apps, so people generally find HEIC a bit annoying if they want to share something with someone. Therefore, you would have to convert the HEIC image to JPG.
Read more: How to transfer photos and videos from iPhone to Android