IP does indeed stand for IP address range. The range is defined using the network that you define + the wildcard that you set.
In your case it will be a range between 10.0.0.0 to 10.255.255.255.
So it will drop all network traffic that has a source IP address between the range above defined.
IP is needed to be declared as previously there were different kind of network traffic that could have been filtered. Nowadays though most traffic is considered to be IP traffic. It is just kept there as a traditional indicator of the type of traffic that is meant to be filtered.
ACLs are very low level implementations of "firewalls". They look at network packet's header information and match them based on the rules defined.