为什么我添加jetty时不是plugin标签而是dependency标签
<!-- jetty -->
<!-- https://mvnrepository.com/artifact/org.eclipse.jetty/jetty-server -->
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-server</artifactId>
<version>9.4.12.v20180830</version>
</dependency>
我从Maven repository网站上找的jetty是长这样的,为什么不是plugin标签啊?