Eclipse icon meaning and how to resolve them

What do these eclipse icons mean and how to resolve them, if there is an issue?
I think is some how contributing to the errors Im getting during compile/build using “mvn test” command (from where pom.xml file is.
Btw, I’m relatively new to Java/Maven and this is my full scale project (selenium automation)

Eclipse project screenshot

Answer

? on the file means there are changes in those files when compared with the version on the repository. What is the exact error you see during build?