"Relevant internships" refers to work experiences that are closely related and applicable to the field or industry that you are interested in or pursuing. Full definition
Putting education first allows this job seeker to include relevant internships near the beginning of the resume so the employer can quickly see that she does have some practical experience in the field. (careerchoiceguide.com)
If you have limited work experience, highlight any work experience gained from relevant internships. (thebalance.com)
Other short - or medium - term targets could include undertaking relevant internships, gaining volunteer experience or visiting careers fairs. (prospects.ac.uk)