Libgdx is an open source, cross-platform development framework, which is designed mainly, but not exclusively, to create games using the Java programming language. Besides Java, Libgdx also makes heavy use of the C programming language for performance-critical tasks, to incorporate other C-based libraries and to enable cross-platform capabilities. Moreover, the framework abstracts the complex nature of all its supported target platforms by combining them into one common Application Programming Interface (API). One of the highlights of Libgdx is the ability to run and debug your code on the desktop as a native application. This enables you to use very comfortable functions of the Java Virtual Machine (JVM), such as Code Hot Swapping, which in turn lets you immediately see the effect of your changed code at runtime. Therefore, it will significantly reduce your time to iterate through different ideas or even to find and fix nasty bugs more quickly.
Another critical point is to understand that Libgdx is a framework and not a game engine that usually comes with lots of tools, such as a full-blown level editor and a completely predefined workflow. This might sound like a disadvantage at first but actually it turns out to be an advantage that enables you to freely define your own workflow for each project. For example, Libgdx allows you to go low-level so you could add your own OpenGL calls if that really became necessary at some point. However, most of the time it should be sufficient enough to stay high-level and use the already built-in functionalities of Libgdx to realize your ideas.