Internships
During an internship you will gain practical experience by, for instance, working at a company or government agency active in Earth Sciences or participating in scientific research.
(Not) compulsory
An internship is in most cases not compulsory, but can definitely help you to get a feeling for actual professional practice. An internship is compulsory if your personal programme focuses on a career outside the academic world (management and society, communications and education). Many employers appreciate experience gained in an organisation.