Web fundamentals · Note 001
DNS is the web's address book.
Websites have names that humans can remember, like example.com. Computers, however, communicate using IP addresses. The Domain Name System (DNS) helps bridge that gap by translating a domain name into information a device can use to reach a service.
When you visit a new website, your device typically asks a DNS resolver for its address. The resolver may already know the answer from a recent lookup. If not, it can follow a chain of DNS servers to find the appropriate record. The result is cached for a period of time, making future visits faster.
The useful distinction: DNS helps your browser find a destination. It doesn't, by itself, download the page or secure the traffic that follows.
Different DNS records serve different purposes. An A record associates a name with an IPv4 address, an AAAA record does the same for IPv6, and a CNAME record aliases one name to another. Understanding these basics makes website setup and troubleshooting far less mysterious.
Security basics · Note 002
What HTTPS actually protects.
HTTPS is HTTP carried inside a secure TLS connection. It gives browsers a way to encrypt information in transit and to verify that the server presents a certificate valid for the site you intended to reach.
During the TLS handshake, the browser and server agree on cryptographic parameters and establish keys for protecting the connection. The browser also validates the certificate chain and the domain name. Once that process succeeds, requests and responses can travel over an encrypted channel.
Important: The padlock means the connection is protected and the certificate checks passed. It does not mean that the website itself is trustworthy or that its content is accurate.
HTTPS is now the default for most of the web, from online banking to ordinary blogs. It helps protect logins, forms, and the pages people read against interception or tampering while data is moving across the network.
Performance · Note 003
Why bandwidth isn't everything.
Bandwidth describes how much data a connection can transfer over time. Latency describes how long information takes to travel between two points. Both matter, but they influence the experience in different ways.
Large downloads benefit from high bandwidth. Interactive activities — opening pages, gaming, video calls, or making many small requests — can feel sluggish when latency is high, even on a connection with excellent download speeds.
Think of it this way: Bandwidth is like the width of a road. Latency is how long the first vehicle takes to reach its destination.
The distance to a server, network congestion, Wi-Fi quality, routing decisions, and application design all contribute. For troubleshooting, it helps to consider latency, packet loss, and bandwidth together instead of relying on a single speed-test number.