Freestyle projects in Jenkins are general purpose projects that allow you to configure just about any sort of build or continuous integration process. With a freestyle project, you have a wide range of options to customize your build process. For example, you can configure your project to run shell scripts, execute Ant targets, run a Windows batch file, or run a Maven build.
Maven projects in Jenkins are specialized projects that are designed to work with Apache Maven. Maven projects are configured using a Project Object Model (POM) file. This file contains information about the project, such as the version of the project, the dependencies, and the build goals. With a Maven project, you can configure Jenkins to execute Maven goals, such as compile, test, and package.