A resume summary is a brief paragraph that provides an overview of the rest of the resume, highlighting key achievements and relevant experience. 

Resume Summary Examples for Students (Plus How to Write One in) | Indeed.com Australia 

Some resume advice may talk about including a "Career Objective" instead of a summary. There is mixed acceptance of resume objectives by employers. Only include an objective if you write it specifically for the job you are applying for and if it adds value to your resume. Remember: employers want to know what you can do for them. A resume objective can often read as what an employer can do for you.