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A MAC address identifies a piece of hardware on a local network; an IP address identifies a location on the internet. One is fixed to the device, the other describes where the device currently is —
Several distinct parts, each doing a specific job — and being able to read them is a genuinely useful security skill, because most phishing depends on people misreading the one part that matters.
POP downloads mail to one device; IMAP keeps mail on the server and synchronises. For anyone using more than one device, IMAP is the correct answer and POP is a source of confusing problems. POP3 was
Through a stored priority list and a continuous signal assessment, which together explain the two behaviours people find most annoying: clinging to a weak network, and joining the wrong one. How
A proxy intercepts traffic for a specific application; a VPN captures traffic from the whole device and encrypts it. The practical difference is scope and encryption, and confusing the two leads
A device that connects wired devices on the same local network, forwarding each frame only to the port where its destination actually is. Most homes do not need one; most homes that run out of router
A subnet is a logically separate section of a network, and networks are divided for three reasons that are worth distinguishing: reducing unnecessary traffic, improving security, and making
Your phone attaches to a foreign network that has an agreement with your own, and your home network continues to authenticate you and to control what you can do — which is why your number, your
It travels through the signalling channel of the mobile network rather than as ordinary data — a design accident from the 1980s that explains almost everything odd about SMS. The origin. SMS was
By establishing a direct path between the two devices wherever possible, which is harder than it sounds because almost every device sits behind a router that blocks incoming connections by default.
Because "5G" describes a family of radio technologies across very different frequencies, and the band you happen to be on matters far more than the generation label on your phone. The three bands,
Through a hierarchy of lookups that once corresponded directly to geography and physical switches, and now mostly corresponds to database entries — a change that number portability forced. The
Through several mechanisms layered on top of each other, because the original telephone network knew your address and the mobile network fundamentally does not. On a landline, the answer is simple:
Because manufacturers set an end-of-support date after which no fixes are issued, and it matters more than for almost any other device — a router sees every packet on your network and is permanently
By continuously changing quality to match your connection — a technique called adaptive bitrate streaming, which is why a stream degrades into blurriness rather than stopping. How the video is
They are defined advertising terms rather than promises, and understanding which one you were given tells you what you can actually hold a provider to. "Up to" speeds described the theoretical
Spectrum is the range of radio frequencies usable for wireless communication — and it is auctioned because it is a genuinely finite shared resource where two users of the same frequency in the same
As pulses of light down a strand of extremely pure glass, guided by a physical effect that keeps the light from escaping even as the cable bends. The physical mechanism. A fibre has a core of glass
Less about raw speed than the marketing suggests, and far more about handling many devices at once — which is the problem actual homes and offices have. Wi-Fi 6 (technically 802.11ax) changed how
Both push Wi-Fi further into a building, and they do it by fundamentally different mechanisms — which is why one usually works well and the other frequently disappoints. What an extender does. It
Through a chain of servers using SMTP, guided by DNS — and the important structural fact is that email is a store-and-forward system with no guarantee of delivery and no reliable confirmation of
A Request for Comments is a numbered document published by the IETF describing a protocol, a procedure or an observation — and the name is a historical artefact that persists, because many RFCs are
Through several techniques operating at different layers, each with different costs, different accuracy and different ease of circumvention — and most real systems combine them. The techniques, in
A deliberate disruption of internet access by a government or an actor acting on its instruction, affecting a population, a region or a service. They have become more frequent, and the techniques are