take a year off是什么意思?这段话的逻辑我搞不清楚.

take a year off是什么意思?这段话的逻辑我搞不清楚.
Charles Deacon is the dean of admissions at Georgetown University in Washington, D.C. He estimates that in the current first-year class of one thousand six hundred students, only about twenty-five decided to take a year off. He says this number has not changed much over the years.
Mister Deacon says the most common reason is to have a chance to travel. But he says international students may take a gap year to meet requirements at home for military duty.