The "web" has evolved into complex marketing, knowledge, and sales delivery systems – involving static base information, graphics, dynamic content driven by a database system, marketing strategies, interactive forms, product management, memberships systems, and payment gateways to handle purchases. And let's not forget social media interaction, visitors to your site who feel compelled to comment on every aspect of your content, and perhaps your own need to expound/blog on various aspects of "whatever" your specialty may be.