求教！~

Heaven7

在申请时看到两个注意事项：
1）You will be asked to supply two letters of reference. The letters should be sent to the NCP program by the referees not by the applicant!
2）The timely arrival of the recommendation letters at the coordinating office is up to applicant's responsibility.
请问：letter of reference 与recommendation letter是否是一个东西？不是的话之间有什么区别？


谢谢了！！~