I realize, when talking about structures, obviously if you say "post hasMany comments" there are many records about comments relating to each post.

Don't understand what context these sort of terms are used in. I'm thinking mainly only in DBAL or talking about design. In any case, when one thing hasMany of another how/where does it show up in application and database logic?

Sorry for the totally newb question, I've tried searching but I keeping finding discussions about such and such hasMany x. If anyone can help refine the question (especially tags), please feel free.