Classless Inter-Domain Routing (CIDR)

Classless Inter-Domain Routing (CIDR) is a method for efficiently allocating and managing IP addresses on the internet. Unlike older systems that divided IP addresses into fixed classes (Class A, B, C), CIDR uses a flexible notation, such as 192.168.1.0/24, where the "/24" indicates the number of bits used for the network part of the address. This allows for more precise control over how IP addresses are grouped, reducing waste and improving routing efficiency. CIDR helps accommodate the growing number of internet-connected devices while managing the limited supply of IP addresses.