what is 360 degree performance appraisal?

the 360 appraisal is that the appraisal given peers, 
subordinates,workers,head of the department etc  that means 
the appraisal given from all the people working in the 
organizations 360 degree appraisal. The half yearly report 
or yearly report of work schedule goes from the company to 
the head quarter of all the workers performance is the 
appraisal  it contains all the demotion, promotion and 
other activities related to the performance.