This is done by an ISP when it takes a block of addresses subnets the block into multiple subnets and then passes out the smaller individual subnets to customers.?

This process is known as subnetting. An internet Service Provider (ISP) takes a large block of IP addresses and divides it into smaller subnets to efficiently allocate resources and manage network traffic. By assigning these smaller subnets to individual customers, the ISP can optimize the use of IP addresses while ensuring each customer has sufficient connectivity. This method enhances network organization and improves overall performance.