I am fairly new in product development and I am trying to work over a product. The problem that I have realized is that people draw diagrams and charts showing different modules and layers.But as I am working alone (I am my own team) I got a bit confused about the interaction I am facing in the development within the programs and I am wondering whether developing a product in modules is real or not?Maybe I am not a great programmer, but I see no boundaries when data start to travel from frontend to backend. 
Is programming in layers real?
design;web development;layers;product