When I run netstat there are some entries such as
TCP [::]:8010 computername LISTENING
What does that mean? It is impossible to search for...
In this case, it means all zeroes, or the IPv6 equivalent of the IPv4
As an example of something that is not all zeroes:
Which is properly "reduced" to:
As an example, it can also be written as:
but that is far less common than just "double coloning" it.
:: is the IPv6 "unspecified" address, equivalent to 0.0.0.0 - the  is notation to separate the address from the port specifier.
A program bound to :: will be given traffic for any actual IPv6 address assigned to the system - it may also receive IPv4 traffic too in the form of IPv6-mapped IPv4 addresses (::ffff:x.x.x.x) although this is dependent on the socket options set by the application.