Remember the cables in the cable vault? There were 8 of them in our example. Well, each of those will head towards a specific serving area, the COs area of coverage is divided into these. Phucked Agent 04 says they terminate in SAIs, or serving area interfaces, but I've personally never seen one. I believe him simply because it makes sense, and you probably should to.
After leaving the cable's SAI it will be divided down to 'lower level' cables, that is, the serving area's are broken down into even smaller areas of distribution. At this point the cable is known as an 'F2' cable. While on the way to an SAI it is known as an 'F1'. F2's terminate in sub-SAI's, which are known commonly as cross-boxes. Note that this isn't the only use of a cross box, just one major use. More on these later.
From a cross-box the cable will be split into even smaller cables, and these will typically head towards neighborhoods. They will emerge at telephone poles(see image below), and serve a street or two.