Dependency and exclusion

I have the following DEPENDENCY to the "Maven Ant Tasks Repository" as follows:

Note: "artifact" represents the Maven Ant Tasks repository.


<artifact:dependecies pathId="dependency.classpath">
<dependency groupId="org.hibernate" artifactId="hibernate" version="3.2.5.ga">
<exclusion groupId=javax.transaction" artifactId="jta"/>


What does "exclusion" mean here?

And, does "dependencies" and "dependency" represent KEYWORDS?

Provided that the Maven Ant Tasks repository is located at:

<project xmlns:artifact="antlib: org.apache.maven.artifact.ant">
</project>



Thanks.