Pv6 Link-Local Addresses (LLAs) are similar to APIPA (Automatic Private IP Addressing) addresses in Windows IPv4 based systems. APIPA addresses are self-configured, non-routable addresses in the range of 169.254.0.0/16. But unlike APIPA addresses, LLA addresses remain assigned to an interface as a secondary address even after a routable address is obtained for that interface.
An LLA address always begins with the prefix "fe80" and is structured as follows:
The first half of the address is written as fe80:: but can be also written as fe80:0000:0000:0000.
The second half of the address represents the interface ID.
Each computer tags an LLA with a zone ID in the form "%ID". This zone ID is not part of the address but changes relative to each computer. It specifies the network interface that is connected either locally or across the network, to the address. You can read more about IPv6 here.
