Why I use Ipv4 address ?

You use IPv4 (Internet Protocol version 4) because it is the foundational language of the modern internet and provides universal compatibility across virtually every connected device and website in existence. While a newer version called IPv6 exists, IPv4 remains the deeply entrenched global standard.

Universal Compatibility & System Support Total Adoption:

Every major router, server, computer, smartphone, and smart gadget manufactured over the last few decades natively supports IPv4.

No Broken Connections:

Much of the internet still runs strictly on IPv4. Using it ensures you can seamlessly access older websites and infrastructure without encountering connection errors.