What's the difference between implementation and compile in Gradle?

Question

After updating to Android Studio 3.0 and creating a new project, I noticed that in build.gradle there is a new way to add new dependencies instead of comp

Answer 1

Compile configuration was deprecated and should be replaced by implementation or api.

You can read the docs at https://docs.gradle.org/current/userguide/java_library_plugin.html#sec:java_library_separation.

The brief part being-

The key difference between the standard Java plugin and the Java Library plugin is that the latter introduces the concept of an API exposed to consumers. A library is a Java component meant to be consumed by other components. It's a very common use case in multi-project builds, but also as soon as you have external dependencies.

The plugin exposes two configurations that can be used to declare dependencies: api and implementation. The api configuration should be used to declare dependencies which are exported by the library API, whereas the implementation configuration should be used to declare dependencies which are internal to the component.

For further explanation refer to this image.