difference b/w center & centre

Some people do make distinctions between the words. For instance, some prefer to treat center as the word for a place or institution and centre as the word for the middle point of something. But while these preferences may be taught in some schools and are perhaps common among careful English speakers in Canada, the U.K., and elsewhere, they are not broadly borne out in 21st-century usage.
There is no difference in meaning between center and centre. Center is the preferred spelling in American English, and centre is preferred in varieties of English from outside the U.S.

Percent of the time center is used rather than centre, by region

  United States 92.2%
    Philippines 87.5%
       Pakistan 54.0%
      Hong Kong 51.8%
     Bangladesh 51.2%
          India 43.8%
       Tanzania 42.5%
      Singapore 40.7%
          Kenya 40.3%
        Jamaica 40.3%
        Nigeria 39.1%
       Malaysia 35.1%
          Ghana 34.4%
      Sri Lanka 33.8%
         Canada 33.0%
    New Zealand 24.2%
        Ireland 20.1%
   South Africa 19.8%
  Great Britain 19.4%
      Australia 18.1%