Nice docs Symfony!

However, [dependency injection] is also one of the most difficult [design patterns] to explain well. This is probably partly due to the nonsense examples used in most [tutorials]. In this chapter, we have tried to come up with examples that fit the PHP world better. As PHP is a language mainly used for web development, we are going to use simple Web examples.

I figure since everyone’s been talking about dependency injection, it might be good to know what they’re talking about.