An IP address space refers to the range of unique numerical labels assigned to devices connected to a computer network that uses the Internet Protocol for communication. Each IP address serves as an identifier, allowing devices to locate and communicate with each other over the internet. There are two main types of IP addresses: IPv4 and IPv6. IPv4 addresses consist of four sets of numbers, while IPv6 addresses use a longer format to accommodate the growing number of devices. The IP address space is crucial for ensuring that each device has a distinct address, preventing confusion in data transmission.