required

The word “required” means necessary or mandatory. In plain terms, something you must do or have — not optional.

“Required” is pronounced rih-KWEYE-uhd (/ɹɪˈkwaɪɹd/ in IPA).

Here is “required” used in a sentence: “Attendance at the orientation is required for all new employees.”

“Required” is an adjective.

“Required” is a very common word in modern English.

They are opposites. 'Required' means something is necessary and must be done or provided — there is no choice about it. 'Optional' means it is left to your discretion; you may do it or skip it freely. A required field must be filled in, while an optional one can be left blank.

'Required' means mandatory — you have no choice but to comply. 'Requested' is far softer; it means someone has asked for something, but you may still decline. A required document must be submitted, whereas a requested one is merely wished for. The gap between them is obligation versus polite asking.

Yes, 'required' is fairly formal and common in official, legal, and academic contexts — 'proof of identity is required.' In casual speech people often say 'needed' or 'you have to.' All convey necessity, but 'required' carries a firm, rule-bound tone that suits instructions and regulations.