What i don't understand is if the pcb is just routed normally using tracks and then there is a polygon placed on top to fill the board or if the polygon(s) are used to connect components, also i do not understand what the through holes are there for. Anything that could help me understand this pcb is greatly appreciated. My goal is to reproduce this pcb using Altium, so anything that gets me going in that direction (tutorials etc.) is greatly appreciated.
Orange polygons [and other shapes] - copper covered with ENIG * On the edge of the board, both sides - mate to edge connector * On the top-side - mount your components there
White polygons [and other shapes] - legend, silk screen
Blue colored area - soldermask
Little holes - via that connect the copper on the bottom to the copper on the top of the board.
Big holes - At the bottom of the bill of materials you'll see ...
EN 5014 Test Point Loop Yellow 1 Keystone VIN 5010 Test Point Loop Red 1 Keystone VOUT 5013 Test Point Loop Orange 1 Keystone GND 5011 Test Point Loop Black 2 Keystone
These test points are PTH components use to monitor your circuit to input voltage and ground, output voltage and ground and shutdown signal.
NOTE: We're talking about a 'demo board' here. In the industry, a demo board usually is something that the supplier [here TI] provides in order to make it easy for an engineer to evaluate a component. Now, I appreciate your interest in reverse engineering the board with a very nice CAD software as a project. Consider requesting a board from TI to use a baseline for your design and for making a first pass at making sure that the circuit runs.
PROBLEM: Moving forward with the information that you have in this application note presents problems. From the schematic, the component [L1] that we're talking about here has at least 5 connections. From the information at hand, you have no idea of the shape or location of these connections. Better get the datasheet [http://www.ti.com/product/lmr62014 ] Five connections in a SOT23. Pfew, that was easy.