Lesson 4 Network Fundamentals – We learned about the open systems interconnection model created by the international organization for standardization. We learned the functions of each layer of the OSI model. Each layer of the OSI model serves the layer above it and is served by the layer below it. We discovered how TCP/IP facilitates communication. Transmission control protocol splits messages into packets and the IP routes them. We learned the difference between TCP and UDP and HTTP and HTTPS.