For a Standard Any2, just choose two of the first three placegetters past the post, in any order. As long as your two selections finish first, second or third, you collect the Any2 dividend.
With a Box Any2 you can choose as many runners as you like, providing two of your selections finish first, second or third, in any order. The more runners you 'Box' in a Any2 the more combinations you get. For example, if you 'Box' four (4) runners, say numbers 1,2,3 and 4, you get six (6) combinations: 1-2, 1-3, 1-4, 2-3, 2-4 and 3-4. Four (4) runners 'Boxed' in a Any2 will cost $6 for a $1 investment.
If you feel there's a 'sure thing' in a race that looks certain to run 1st, 2nd or 3rd, then a Banker Any2 is a perfect type of bet. Your 'Banker' would be the 'sure thing' and you can group it with any number of other runners in the race. Providing your 'Banker' runs 1st, 2nd or 3rd and one of your other selections finishes 1st, 2nd or 3rd with your 'Banker', you win the Any2. The more 'other' selections you take, the more combinations you get. For example, if you took a 'Banker' with six (6) other runners you would get six (6) combinations. This bet would cost $6 for a $1 investment on each combination.
A Multiple Any2 allows you take as many runners as you like for each placing. For example, you can take three (3) runners for first and five (5) runners for second. Provided that one of your runners selected in the first leg places either first, second or third, and one of your runners selected for the second leg fills any of the other two placings (third, second or first), then you win the Any2.