Necessary

If something is necessary, it is very important, otherwise something will be impossible, or it will not work as it should do.  The opposite is unnecessary.

To travel from Europe to America it is necessary to cross the ocean.
A car is necessary for my work.  I can not do my work without a car.
There is no need to do that.  It is quite unnecessary.

Something that is necessary is a necessity.
The "bare necessities of life" are things like food, clothes and shelter (things you need to keep alive).

Category:Basic English 850 words