To become a proficient digital citizen or IT professional, you must stop thinking of these as separate entities. When your video lags, don't just blame "Wi-Fi." When a program crashes, don't just blame "Windows." Learn to trace the flow of data from a server on the net, through your router, into your network card, managed by your OS, and finally processed by your software.
Master this trinity, and you master the digital world. pc+software+net
Antivirus and firewalls sit between your PC software and the net. They inspect every packet. A poorly optimized security suite can reduce your network throughput by 40%. Modern solutions, however, use cloud-based heuristics—offloading the heavy analysis to the net, saving your CPU. To become a proficient digital citizen or IT