If you say that something is vital, you mean that it is necessary or very important.
unimportant , inessential
The port is vital to supply relief to millions of drought victims.
这个港口至关重要,它给数百万旱灾灾民提供救济物资。
It is vital that parents give children clear and consistent messages about drugs.
至关重要的是,父母们给子女提供关于毒品的明确且一致的信息。
It is vital that records are kept.
保存好记录是至关重要的。