Added DynDNS Explanation to README.md

Author: TRC-Loop

README.md

@@ -25,8 +25,26 @@
 
 A Simple Webinterface to manage all your DynDNS Domains!
 
+## DynDNS
+
+**Dynamic DNS (DynDNS)** is a technique that lets a fixed hostname always resolve to the current public IP address of a device whose IP changes frequently.
+
+*Example:*  
+You own the domain `myhome.dyndns.org`.  
+When your ISP assigns a new IP to your home network, the DNS record for `myhome.dyndns.org` is updated automatically, so anyone can reach your home services by simply typing that hostname, regardless of the actual IP at the moment.  
+
+### DNS record types involved
+
+| Record | What it stores | Typical use in DynDNS |
+|--------|----------------|-----------------------|
+| **A**  | IPv4 address   | The hostname’s IPv4 mapping. Updated whenever the IPv4 address changes. |
+| **AAAA** | IPv6 address | The hostname’s IPv6 mapping. Updated when the IPv6 address changes. |
+| **DynDNS record** | A special DNS update mechanism (often a TXT or SRV entry used by the provider) | Signals to the DNS provider that the hostname should be refreshed automatically; the provider’s API updates the A/AAAA records on your behalf. |
+
+
 ## Installation
 
 Coming Soon!
 
 
+