Your internet service provider (ISP) is a good place to start. They will have all kinds of electronic components that sorts your ‘Netflix’ signal from my ‘Amazon’ signal, and launches it into the PON (Passive optical network) that supplies your home. Surprisingly, from this point onwards, there are no more electronics until the signal reaches your house. This could be up to 20km but on average, less than 11km. This signal is made up of pulses of light that travels through the various fibres, splices, connectors etc.
When your particular fibre enters your local area, it will pass through a number of green street cabinets, until it reaches the one closest to you. At this point, an engineer will usually cut a window into the large cable allowing your fibre to be separated out. The trunk cable will then pass on to the next green cabinet to supply internet elsewhere.