What Is DNS?
DNS stands for Domain Name System. Every website on the internet lives at a numerical IP address, something like 196.18.24.45. Humans are not well-suited to remembering strings of numbers, so DNS acts as an intermediary layer that maps memorable domain names to the correct IP addresses behind the scenes. When you type a URL into your browser or click a link, a DNS query happens almost instantly in the background before any page content is fetched.
The process works through a hierarchy of nameservers. Your device first checks its own local cache to see if it has recently resolved the domain. If not, it queries a recursive resolver, usually provided by your ISP or a public service like Google's 8.8.8.8. That resolver works up the chain, querying root nameservers and then the authoritative nameserver for the specific domain, until the correct IP address is returned. The whole process typically completes in milliseconds, though the first visit to a domain may take slightly longer before the result is cached.
DNS records come in several types, each serving a different function. An A record maps a domain to an IPv4 address. An AAAA record does the same for IPv6. MX records route email. CNAME records create aliases. TXT records are used to verify domain ownership and configure services like Google Search Console or email authentication protocols such as SPF and DKIM. Understanding which record type to edit is essential when setting up a new website, migrating a domain, or configuring email for your business.
For South African businesses, DNS configuration is particularly important when registering .co.za domains through ZACR-accredited registrars. The registrar controls where your nameservers point, and getting this wrong means your website, email, or both will not function correctly.
DNS In Practice
Consider a Johannesburg-based e-commerce retailer that has just launched a new website on a new hosting provider. The developer updates the A record in the DNS settings to point to the new server's IP address. Because the old DNS record had a TTL (Time to Live) of 24 hours, some visitors will still be directed to the old server for up to a day while resolvers around the country clear their caches. To minimise this disruption, a good practice is to reduce the TTL to 300 seconds (five minutes) at least 24 hours before the migration, so that the changeover happens quickly once the new A record is published.
DNS performance also has a direct bearing on website speed. Slow DNS resolution adds measurable latency before a single byte of your page is transferred. Services like Cloudflare's 1.1.1.1 or Google's 8.8.8.8 offer faster resolution than many South African ISP-provided resolvers. Using a premium managed DNS provider with globally distributed anycast nodes reduces lookup time for international visitors, which becomes relevant as South African businesses expand into other African markets.
What DNS is
DNS (Domain Name System) is the system that translates human-readable domain names (like a website's address) into the numerical IP addresses that computers use to locate each other on the internet, effectively acting as the internet's address book. When someone enters a domain name in their browser, DNS is what looks up the corresponding IP address of the server hosting that site, so the browser can connect to it, all happening behind the scenes in fractions of a second. Because people remember names rather than numeric IP addresses, DNS provides the essential translation that lets us use memorable domain names while computers use the underlying IP addresses. DNS involves several types of records that configure how a domain works: for example, records that point the domain to the server's IP address (directing where the website is hosted), records that direct email for the domain (MX records), and other records for various services and verifications. Managing a domain's DNS, through a DNS provider or registrar, is how you control where the domain and its services point, such as directing the domain to a new host when you move a website, or setting up email. DNS changes take some time to take effect across the internet, a process called propagation, because DNS information is cached in many places. Understanding DNS matters because it underpins how domains connect to websites and services: whenever you set up, move or configure a domain, website hosting or email, you are working with DNS, so knowing what DNS is, the system that maps domain names to servers, helps a business understand and manage the technical foundations of its website and email, and appreciate why changes like moving a site or setting up email involve DNS configuration and propagation time.
DNS propagation and TTL
Two practical aspects of DNS that businesses encounter are propagation (the time DNS changes take to take effect) and TTL (a setting that influences it), both relevant when making DNS changes such as moving a website or updating records. DNS propagation is the period during which a change to a domain's DNS records spreads across the internet and is picked up everywhere, because DNS information is cached (stored temporarily) by servers and devices around the world, a change does not take effect everywhere instantly; instead, caches gradually update to the new information, so for a time some users may still be directed by the old (cached) records while others get the new ones, until propagation completes. This is why, after changing DNS (for example, pointing a domain to a new host), the change can take some time to be fully live for everyone, and a website move may appear to take effect for some visitors before others during propagation. How long propagation takes varies, often from a short time up to a day or so, depending on caching and the TTL setting, so the common advice is to allow up to around 24 to 48 hours for DNS changes to fully propagate, though it is frequently faster. TTL (Time To Live) is a setting on DNS records that specifies how long the record may be cached before it should be refreshed, in effect telling servers how long to keep the cached value before checking for updates; a lower TTL means caches refresh more often (so changes propagate faster, but with slightly more DNS lookups), while a higher TTL means longer caching (fewer lookups, but slower propagation of changes). TTL matters because it influences how quickly DNS changes take effect: lowering the TTL in advance of a planned change (such as a site migration) means the change propagates faster when made, which is a common practice before migrations to reduce downtime, after which the TTL can be raised again. For a South African business, understanding propagation and TTL is useful when making DNS changes: expect DNS changes (like moving a website or updating records) to take some time to fully propagate (commonly allowing up to a day or two, though often faster), and consider lowering the TTL beforehand if a fast, smooth change is important, so the update takes effect quickly. Knowing that DNS changes are not instant, and that TTL governs the caching that affects propagation, helps a business plan website moves and DNS updates sensibly, allowing for propagation time and using TTL appropriately to manage how quickly changes take effect.
FAQ
How long does DNS propagation take in South Africa?
DNS propagation typically takes between 15 minutes and 48 hours depending on your TTL settings and the resolvers used by your visitors' ISPs. In South Africa, major providers like Telkom and Vodacom update their resolvers frequently, so most changes are visible within a few hours of updating your records.
What is a DNS TTL and why does it matter?
TTL (Time to Live) tells DNS resolvers how long to cache a record before checking for updates. A lower TTL means faster propagation when you change records but causes more queries to your nameserver. Most South African businesses set TTL between 300 and 3600 seconds for a good balance between speed and server load.