Definition [Cambridge Dictionary]: 1. to make an arrangement or meeting certain, often by phone or writing [确认，确定（安排或会议）]

2. to prove that a belief or an opinion that was previously not completely certain is true [确定；证实；肯定]

Example:

Six people have confirmed that they will be attending and ten haven't replied yet.

有6人已确认将参加，还有10人尚未答复。

Her announcement confirmed (that) she would be resigning as CEO.

她的声明证实了她将会辞去首席执行官职位。

The smell of cigarette smoke confirmed what he had suspected: there had been a party in his absence.

烟味证实了他的猜疑：他不在时这里举行过聚会。

Definition [Cambridge Dictionary]: to prove that something exists or is true, or to make certain that something is correct [证明；证实]

Example:

These numbers are surprisingly high and they'll have to be verified.

这些数字高得令人吃惊，必须加以核实。

Under interrogation, she verified (that) the tapes were authentic.

经过审问，她证实那些录音带是真实的。

这两个动词都有“证实”之意。

confirm : 侧重以事实或以不容置疑的陈述来证实某事的正确与真实。

verify : 强调以具体的事实和细节为证据。