require
If you require something, you need it or want it.
Is there anything you require?
We cannot guarantee that any particular item will be available when you require it.
Require is a formal word. You do not usually use it in conversation or in less formal writing. Instead, you use need or want.
I won't need that book any more.
All they want is a holiday.
If something is required, it must be obtained so that something else can be done.
Parliamentary approval would be required for any scheme.
An increase in funds may be required.
If you are required to do something, you must do it, for example because of a rule or law.
All the boys were required to study religion.