An electrophilic substitution reaction is an organic reaction in which the negatively charged part of an atom or molecule (a nucleophile) seeks out and then reacts with a positively charged part of another.
In a non-electrophilic substitution reaction, two molecules don't exchange electrons and instead combine to form a new molecule without giving up energy.
Non-electrophiles are typically more stable than electrophiles and can undergo reactions at room temperature or even under mild conditions like water vapor or lighter gases.
It seems that electrophilic substitution results in a product with more carbons, while non-electrophilic substitution results in a product with fewer carbons.