demand vs require

demand

verb
  • To request forcefully. 

  • To require of someone. 

  • To claim a right to something. 

  • To ask forcefully for information. 

  • To issue a summons to court. 

noun
  • An urgent request. 

  • The desire to purchase goods and services. 

  • An order. 

  • The amount of a good or service that consumers are willing to buy at a particular price. 

  • A forceful claim for something. 

  • A requirement. 

  • More precisely peak demand or peak load, a measure of the maximum power load of a utility's customer over a short period of time; the power load integrated over a specified time interval. 

require

verb
  • To demand, to insist upon (having); to call for authoritatively. 

  • To demand of (someone) to do something. 

  • Naturally to demand (something) as indispensable; to need, to call for as necessary. 

How often have the words demand and require occurred in a corpus of books? (source: Google Ngram Viewer )