Computer Networks:
Computer networking refers to connected computing devices (such as laptops, desktops, servers, smartphones, and tablets) and an ever-expanding array of IoT devices (such as cameras, door locks, doorbells, refrigerators, audio/visual systems, thermostats, and various sensors) that communicate with one another.
Learning Tutorials: Computer Networks
Introduction to Computer Networks
OSI Model Vs. TCP/IP Protocol Suite
Physical Layer Communication
Application Layer
Domain Name System
Transport Layer