What a wildcard mask is, how it relates to a subnet mask, how to compute one for any network, and how Cisco ACLs use host and any.
A wildcard mask tells an access list which bits of an address matter. A 0 bit must match the configured address; a 1 bit is ignored.
For a /24 the subnet mask is 255.255.255.0, so the wildcard is 0.0.0.255. For a /26 (255.255.255.192) it is 0.0.0.63. For a /20 (255.255.240.0) it is 0.0.15.255. Count the host bits: the wildcard covers 2host bits addresses.
permit 10.1.0.0 0.0.255.255 matches anything whose first two octets are 10.1. Apply the mask the same way you find a network address: 10.1.37.9 AND 255.255.0.0 is 10.1.0.0, which equals the line, so it matches. 10.2.0.1 gives 10.2.0.0: no match.
host 10.1.1.5 is shorthand for 10.1.1.5 0.0.0.0: every bit must match. any is 0.0.0.0 255.255.255.255: no bit has to match.
Lines are checked top-down and the first match wins. A packet that matches no line hits the implicit deny at the end of every ACL. Put specific lines before general ones, and remember that a permit any at the top makes everything below it dead.
Wildcards do not have to be contiguous. 0.0.254.255 ignores every bit except the lowest bit of the third octet, which matches only even third octets. The exam rarely asks it, but it explains why the mask is a bit pattern, not a prefix length.
More on this topic: ACL wildcard mask practice, with sample questions and the full list of question types.