What is maven?
Maven is a project management tool. It will help you define project structure and define group ID, artifact name, your CI URL and many more things about the project you can include into Maven.
Most of the time we use maven to manage the dependencies.
So, when you use Maven, it will put all your dependency into the central location and all your projects will use dependency from there. It will ultimately reduce your project size.
Say, you have the project where you are using Selenium and Cucumber dependency
your project size will be around 25 MB.
If you use Maven, all you need is just one pom.xml file and inside pom.xml file you can define your Selenium and Cucumber dependency. So, maven will automatically download it and add it to your build path.
So, your project size will be reduced to some KBs like approx 500 KBs.
Also, updating and managing dependencies will be easy with maven.
What is the dependency?
Dependencies are set of the JAR files that are required by your project