Im not entirely sure on what sort of explanation you want but ill give it a whirl... Oh and i was getting the idea you wanted code.. sorry for that..
anyway getting to my explanation
Using a database instead of Copying Code and updating the site entirely is a useful thing. And has really changed the way ive done things with websites.
Now using a databse to run your site is quite fast depending on your host, what type of database your using and how much data is actually in the database..
Now making this practical to use..
I guess mainly not having to update code and uploading a new file everytime to your host when you add something. When doing this if you have a section requires extra bits on other pages it can be a real hassle. Using a database will eliminate all that. Now you dont really require a database you can use flatfiles. Yet it is very slow but with small amount of traffic and not much data to handle it can be quite an effective method..
I cant see what could be easier than using a database.. As you can manipulate the data as much as you please to make the best result once and not have to go over it all the time... I mean here adding things like Italics, bold etc i think you get what im saying..
Doing this all the time can start to become very time consuming. Although to do it in a database you may need to add that html code or BBcode depending on how well you have set up your code.
TO finish off storage.. Keeping a whole lot of data in one spot rather than in all your html files etc, is so much better and i see it as being a much more practical solution..
Its probably not great depth.. but i hope it helps in some way.