In academia there is some overlap between reports and essays, and the two words are sometimes used interchangeably, but reports are more likely to be needed for business, scientific and technical subjects, and in the workplace.
Whereas an essay presents arguments and reasoning, a report concentrates on facts.
Essentially, a report is a short, sharp, concise document which is written for a particular purpose and audience. It generally sets outs and analyses a situation or problem, often making recommendations for future action. It is a factual paper, and needs to be clear and well-structured.