In many ways, Kotlin is considered a replacement for Java. While it is not compatible with syntax, it is interoperable with Java code and libraries. Kotlin also has its own libraries that were created with its community's early development through an API for Android apps.
In Java, a lot of redundancy results in verbose and thus longer code. Kotlin is more modern and has been simplified, making it easier for beginners to learn. Kotlin focuses on stripped down, functional code and avoids repetitive "boilerplate" code. The language features null safety, eliminating null pointer exception errors. Semicolons at the end of every line are not needed, although Kotlin does not have an issue if a developer uses them out of habit. Additional features reduce the complexity and length of code needed to achieve an end goal.
Kotlin was developed by JetBrains in St. Petersburg, Russia with additional help from open source programmers. At Google IO 2017 conference, Google announced that Kotlin would be the first officially supported program added to Android Studio. Aside from Android apps, Kotlin is also useful for server-side and web apps.