Summer school (or summer university) is a school, or a program generally sponsored by a school or a school district, that teaches students during the summer vacation.
In elementary and middle school, these programs are usually non-academic, though some are used for remedial instruction.
In high school, college or university, students can enroll in classes for credit to be taken into account in their grade point average or their transcript. Generally, this credit is in one of two categories: remediation or advancement. For remediation, the summer school is used to make up credits lost through absence or failure. For advancement, the summer school is used to obtain credit for classes to accelerate progress toward a degree or in order to lessen the load of courses during the regular school year. Sometimes, if a student fails summer school, he or she might repeat a grade although this doesn't happen often.
In academia the term can also refer to a type of conference. Typically, established academics will give presentations on advanced topics in a field to postgraduate students. This type of summer school is often organized at a national or international level, and no credits are awarded. In addition, a college or university sometimes offers a summer program for teachers or other professional workers wishing to round out their professional or general education. Some summer schools are for the general public involving no examinations and are not for degree purposes.