If you’re reading this article, you can thank an internet service provider.
What is an ISP?
Internet service providers, or ISPs, are companies or organizations that provide you with access to the internet.
ISPs can also offer other options, like web hosting and email services, and they can range in form from giant telecommunication companies to small nonprofits.
When you connect to your ISP, you join its network to access the internet – whether that’s through a browser, a streaming platform, or an app on your phone. ISPs are also interconnected, and you can connect to many networks as you access different sites.
Some of the most prominent ISPs include:
ISPs can provide Wi-Fi and Ethernet
Wi-Fi is a wireless internet connection that can be accessed through a router, while Ethernet requires a physical wire (known as an Ethernet cable) that connects your modem to your computer, TV, or video game console.
You can have an ISP that works with both. To be able to do that, you simply need a router that also has an Ethernet port. ISPs that allow for both Wi-Fi and Ethernet connections accomplish this through what’s called a “mixed network.”
A Domain Name System (DNS) server is a fundamental part of the backbone of the internet – without it, it would be impossible to use a web browser to find websites.
You can think of the DNS server as a phone book. When you ask your computer to load a website, the DNS server matches the website’s name with the right IP address. This lets your computer find and load it properly.
How does a DNS server work?
When you enter a URL, what you’re really doing is asking your computer to find and connect to another IP address. To do this, it uses a set of related servers, all of which form the DNS server:
The DNS recursive resolver
The root nameservers
The TLD nameservers
The authoritative nameservers
Here’s how it works.
All this happens in a matter of seconds – if your internet is very fast, or you’ve visited the website recently (see below for more information), it can happen in milliseconds.
Caching can avoid calling the DNS server
If you’re visiting a new website, your browser will go through the entire process outlined above. But if it did this for every single website, things could get slow – that’s why websites you’ve visited recently are stored in your web browser’s cache.
When you try to load a website, the DNS server will first check your cache to see if the IP address is already saved there. If it is, it’ll retrieve the IP address directly from the cache, which saves time.
Each entry in the cache has a time limit associated with it, referred to as the TTL (time-to-live). The TTL for any IP address is generally about 48 hours, and once that passes, the IP address will disappear from your cache. This means that the DNS server will have to go through the whole recursive search process again.
Changing your DNS server
As a general rule, your web browser uses a standard, public DNS server, usually configured and maintained by your internet service provider.
Some advanced users manually change their DNS server, though. This can boost your internet speed and protect your privacy.
Changing your DNS can be done via your computer’s “Network” menu, in the Settings app. If you’re looking for a new DNS, you can try the Google Public DNS or any number of other custom DNS servers.