The file build.gradle describes the default actions and tasks launched by 'gradle' command in the appropriate folder.
Gradlew is an executable file created by the gradle wrapper plugin, to replace the normal gradle executable for a project
"I naively assumed that gradlew is better than ivy then when i created my build.gradle the dependency management is even greater mess than of ivy s for the first look"
from question "* (no title is found for this review)"
"Although build.gradle has a higher priority so the value in androidmanifest.xml will be ignored by gradlew while building your application"
from question "Your APK's version code needs to be higher than XX in playstore developer console"