The buildscript
is for dependencies of your build files. You want to add a repository there if, for example, a task in your build.gradle
needs a plugin that is not found in the standard Gradle distribution, like a gwt wrapper.
The allprojects
is for dependencies needed by your application, like log4j, Guice, Guava and so on.
Also, be warned that using mavenCentral
for retrieving dependencies is a bit discouraged, because if the network is down or if the project is removed from their repositories, you won't be able to build your project anymore