progression vs stepping

progression

noun
  • The act of moving forward or proceeding in a course; motion onward. 

  • A sequence obtained by adding or multiplying each term by a constant. 

  • chord progression 

  • The act of moving from one thing to another. 

  • Development, increase, evolution. 

  • The making an exercise more exerting by manipulating the details of its performance like loaded weight, range of motion, angle, speed. 

stepping

noun
  • The act of taking a step. 

  • A specific iteration of a model of central processing unit, often distinguished by the addition or removal of features compared to earlier examples of the same processor, or the presence, or lack thereof, of specific bugs. 

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