Difference between Require and Necessary

REQUIRE vs NECESSARY: NOUN

Such things, in respect to infants, lunatics, and married women, as are requisite for support suitable to station.
A thing that is necessary or indispensable to some purpose; something that one can not do without; a requisite; an essential; -- used chiefly in the plural.
A privy; a water-closet.
Anything that is necessary or indispensable; that which cannot be disregarded or omitted: as, the necessaries of life.
Something indispensable.
Bathroom, toilet, loo
Anything indispensable

Such as must be; impossible to be otherwise; not to be avoided; inevitable.
Impossible to be otherwise, or to be dispensed with, without preventing the attainment of a desired result; indispensable; requisite; essential.
Acting from necessity or compulsion; involuntary; -- opposed to free.
Needed, required
Required by obligation, compulsion, or convention.
Logically inevitable.
Unavoidably determined by prior conditions or circumstances; inevitable.
Needed or required: : indispensable.
Unavoidably determined by prior circumstances
Absolutely essential

Consider obligatory
=Syn. 2–4. Request, Beg, etc. (see ask), enjoin (upon), prescribe, direct, command.
To have need or necessity for; render necessary or indispensable; demand; need; want.
To ask or order to do something; call on.
To ask or claim, as of right and by authority; demand; insist on having; exact.
To ask for as a favor; request.
Request and expect
To search for; seek.

Such as must be; that cannot be otherwise.
Such that it cannot be disregarded or omitted; indispensable; requisite; essential; needful; required: as, air is necessary to support animal life; food is necessary to nourish the body.
In law:
Requisite for reasonable convenience and facility or completeness in accomplishing the purpose intended: as, the land necessary for building a railroad.
Naturally and inseparably connected in the ordinary course: as, necessary consequences.
Acting from compulsion or the absolute determination of causes: opposed to free. See free.
Synonyms Necessary, Essential, Requisite, Needful. The following remarks refer to the application of the words to ordinary practical affairs, not to philosophy. Necessary is so general a word that it covers all the others, and has the additional sense, which they do not have, of inevitable. Essential is an absolute word, noting that which is a part of the chief end of the action, or of every mode of bringing that end about. Requisite is less strong than essential, and needful is less strong still; yet each is strong and emphatic, applying to that which is imperatively needed. Needful generally applies to concrete, and often to temporary, things: as, knowledge of the countries visited is requisite, and even essential, to enjoyment of travel, but money is needful in order to be able to travel at all. Needful is often applied to that which must be supplied to produce or effect a perfect state or action.

Needed, Obligate, Requirement, Entail, Call for, Command, Demand, Ask, Take, Want, Expect, Compel, Need, Involve, Necessitate

Adequate, Need, Appropriate, Sufficient, Imperative, Needful, Obligatory, Inevitable, Requirement, Indispensable, Necessity, Requisite, Essential, Required, Needed

Stipulate, Needed, Obligate, Requirement, Call for, Command, Demand, Ask, Take, Want, Expect, Compel, Need, Involve, Necessitate

Adequate, Need, Appropriate, Sufficient, Imperative, Needful, Obligatory, Inevitable, Requirement, Indispensable, Necessity, Requisite, Essential, Required, Needed

For example, standards for consulting services do not require independence, but standards for reviewservices do require independence.
Some require initial training and practice to be used effectively; progressive muscle relaxation, systematic relaxation, and autogenic training are skills that require some practice.
The list may be more detailed than you may require, or it may not list items you will require.
Although the model regulation does not require that policies include infation protection, it does require that insurers offer consumers optional protection.
Joint resolutions require the approval of both the Assembly and Senate but do not require approval by the Governor.
Some states only require one director, but the majority of states require a minimum of three directors.
All of these features can be unkind to properties and often require cleaning and maintenance beyond what humans require.
The Standards of Practice require inspectors to inspect attic ventilators and report deficiencies but do not require that they be operated.
Many states require planned program hours in a school setting and some require years of professional education or counseling experience.
He revealed that some civil crimes require restitution, a few require the death penalty.

Accordingly, risk taking is necessary in infrastructure projects.
Additional documents may be required as deemed necessary.
And if necessary we can risk a jump.
HPDetermine price and source of necessary sublet operations.
If correction is necessary, do it in private.
If the answer is no, revisions are necessary.
Board deems appropriate or necessary in the circumstances.
The kinds of expertise necessary to develop decision support analysis tools differ from the expertise necessary to develop data capture and database management tools.
Retail Sale Tags, and Merchandise Tags are a necessary part of every retail store display and provide necessary information to your customers.
If it is necessary to change a term, it may be necessary to draft and incorporate an amendment or extension.