Ant and Maven are different building tools in Java. Both the tools are considered good but with slight differences. However, Maven is widely preferred to Ant, which is an older tool.

A build management/reporting tool, Maven is intended to take Ant to the subsequent level. When compared to Ant, Maven is considered to be a comprehensive Java tool.

Ants do not come with formal conventions such as a common project directory. In this case, you might have to look for the sources and where to keep the output.  Though informal conventions have evolved over time, it has not yet been codified. On the contrary, Maven consists of conventions. This means that there is no need for you to look for the source code.

While Ant is procedural, Maven is declarative. In Ants, you have to specifically order what should be done.  Maven takes care of all the directories once the files are stored in the pom.xml file.

Another difference that can be seen is that Ant does not have a life cycle whereas Maven has a life cycle. In Ant, one has to manually assign a series of tasks to each goal. Once Maven is used, it gives out a command to execute the series of tasks until it reaches a life cycle. With this, Maven executes a number of default plugins, which leads to compiling and creating JAR.

Ant does not have a model and it extends using shell based commands. Ant uses Java classes. Instead of the shell commands, the files are XML based in Ant. When comparing he flexibility, Maven is more flexible than Ant and that is why people prefer it to the other.

It can also be seen that the scripts in Ant are not reusable, where as Maven comes with reusable plugins.

Summary

1. Maven is widely preferred to Ant, which is an older tool.
2. Ants do not come with formal conventions such as a common project directory.  On the contrary, Maven consists of conventions.
3. While Ant is procedural, Maven is declarative. In Ants, you have to specifically order what should have to be done.  Maven takes care of all the directories once the files are stored in the pom.xml file.
4. Another difference that can be seen is that Ant does not have a life cycle whereas Maven has a life cycle.
5. The scripts in Ant are not reusable where as Maven comes with reusable plugins.

Rating: 8/10