Here's a good summary of reference what networking and application models are, and what are examples of them at each of OSI layers.    

This is a next article in series about OSI layer 1 - in previous articles we looked  at Introduction to OSI Layer 1, then

Here is a nice subnet chart to help you memorize cidr notation and mask values.  

Back in the day for Layer1, there were 10Base-2 (Thinnet) and 10BaseT (Thicknet). These types of layer one technologies used coaxial cable on shared bus systems. Really - just to repeat the layer one

In our previous article, Everything you need to know about POTS