Securing the web applications, security recommendations, object-oriented programme, and OOP principles.

Write a short summary of 300-400 words on securing the web applications, security recommendations, object oriented programme, and OOP principles.

Just a small answer for Q2: from 9.5.1 figure 9.7 it is my opinion that this figure has an error. this FS represents the BNF in the previous paragraph. Do you agree or disagree that the figure has an error. If you agree, what is the error?