According to RFC 4291, Section 2.7: Multicast Addresses, the first 8 bits (FF in FF0X) at the beginning of identifies the address as a muticast address.
The flags, the next 4 bits, (the first 0 in FF0X) in the question indicate:
... a permanently-assigned ("well-known") multicast address, assigned by the Internet Assigned Numbers Authority (IANA).
The next 4 bits, (the last hex value 0 or 2 in FF00 or FF02) define the scope:
0 reserved [...] 2 Link-Local scope [...] The reserved scope is reserved for future use.
The Link-local scope means, that packages within that scope will never be routed and therefore cannot leave the subnet.
So the addesses mean he following:
::1:This is the loopback address, whose IPv4-equivalent is127.0.0.1.fe00::0: Can be compared to the Class E address space in IPv4, therefore it's in the reserved scope; reserved for future use.ff02::1: The group of all IPv6 nodes (including the routers) in the Link-local scope, whose IPv4-equivalent is224.0.0.1.ff02::2: The group of all IPv6 routers in the Link-local scope, whose IPv4-equivalent is224.0.0.2.ff02::3: This exists no longer an is unassigned at the moment. Earlier it stood for the group of all hosts (excluding the routers) in the Link-local scope.
Further reading / References:
- RFC 4291: IP Version 6 Addressing Architecture
- RFC 6890: Special-Purpose IP Address Registries
- RFC 7346: IPv6 Multicast Address Scopes
- RFC 2365: Administratively Scoped IP Multicast (see section 8)
- IANA: IPv4 Multicast Address Space Registry
- IANA: IPv6 Multicast Address Space Registry
- IANA: IPv6 Address Space
