It is the study of social and interpersonal human relations. It helps in understanding the humans better and build a rapport with them. It is also defined as the ability to work effectively with other people.
The human relation skills are vital for success in most of the jobs. These skills become all the more important in the cases of front end jobs like sales person, receptionist, etc. as the employee has to meet different people as part of his job. Also, for top executives, the HR skills are very important as they help them manage their teams, and lead them effectively.