To compile a maven project we use the following command.if some files dont match with online repositry they are downloaded.If all files are present in our local repo nothing will be downloaded

mvn compile

To validate our project whether it is as per maven standards

mvn validate

To below command cleans everything i.e target folder which is present in the project folder is deleted

mvn clean 

To execute the project we use below command.It will genereate some apache reports once execution is complete.

mvn test

To run our project and generate maven specific surefire reports instead we use the below command.Reports will be generated in target/site folder

mvn surefire-report:report