The difference between "本“ and "这” , although they both have the meaning of "this",
however , "本“ also carries the meaning of " point of issue" at the same time.
For example: 本周:this "particular" week being talk about, or 这(一)周:this week.
本章:this particular page under discussion, or 这(一)章: this page.
本段:this particular section being talk about, or 这(一)段:this section.