There are two main operating systems commonly being used by mobile handset manufacturer.
1. Android - is open source mobile software which is designed to use for touch screen mobile phones. You can find android software on Samsung, LG, Huawei and Google phones. You can download all the apps you need from the Play Store
2. IOS - Apple operating system used by exclusively by Apple iPhone’s, iPad’s and iPod Touch. You can download all the apps you need from the Apple App Store