OSI Model

Network Hardware & Interfaces — The Physical Layer Still Matters There’s a tendency in modern IT to skip past the physical layer. Cloud, software-defined networking, and virtualization have made it easy to abstract away the hardware. But the physical layer is still where most connectivity problems originate — and where a solid foundation separates reliable infrastructure from constant firefighting. ...

TCP/IP Addressing & Protocols — The Language of the Internet Everything that happens on a network — every webpage loaded, every email sent, every video streamed — depends on TCP/IP. It’s not just a protocol. It’s the foundational language that makes networked communication possible. Understanding it deeply separates people who can use networks from people who can build, secure, and troubleshoot them. ...