Mobile apps are software applications designed to run on mobile devices such as smartphones and tablets. They can be categorized into two main types: native apps and web apps.

Native apps are designed specifically for a particular mobile operating system, such as iOS or Android, and are installed directly onto the device.
They typically offer a higher level of performance and a more integrated user experience, as they can access the device's hardware and software features, such as the camera, microphone, and GPS. They can also be used offline and can send push notifications to the user.
However, developing and maintaining native apps for multiple platforms can be time-consuming and expensive.

Web apps, on the other hand, are essentially websites that are designed to be accessed through a mobile browser. They are not installed directly onto the device and can be accessed from any device with an internet connection.
They are generally easier and less expensive to develop and maintain than native apps, as they can be designed once and deployed across multiple platforms.

However, web apps may not offer the same level of performance and functionality as native apps, as they do not have access to the device's hardware and software features.

Mobile apps have become increasingly popular in recent years, as more and more people use smartphones and tablets as their primary devices for accessing the internet and performing various tasks. Mobile apps are used for a wide range of purposes, including social networking, entertainment, productivity, e-commerce, education, and more. Many businesses have also developed mobile apps to improve customer engagement, increase sales, and streamline their operations.