同为教练的coach instructor trainer有何区别（三大教练认证）

A coach is someone who trains a person or team of people in a particular sport.=trainer也就是特指体育教练An instructor is someone who teaches a skill such as driving or skiing. In American English, instructor can also be used to refer to a schoolteacher or to a university teacher of low rank.可指任何技能的教练比如潜水滑冰等等，在美国也指较低职称的教师