centering vs focal point

centering

noun
  • The process of moving something to a centre, normally before some other process. 

  • A type of formwork which serves as a temporary structure during the construction of arches and bridges. 

focal point

noun
  • The centre of any activity. 

  • A solution that people will tend to use in the absence of communication, because it seems natural, special, or relevant. 

  • A focus; a point at which rays of light or other radiation converge. 

  • A feature that attracts particular attention. 

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