This is a "canned" response with the assumption you have a ten day MYW ticket with both the Park Hopper and Water Fun options.
Hopefully this will make it a little clearer. In effect you have two tickets with different privledges on one card. Everything expires 14 days after first use unless you have the no-expire option.
You have ten days of access to the four major parks (AK, EC, MGM, MK), and may visit more than one major park on a single day without any extra charges. Without the Park Hopper option you can only go to one major park per day.
You have six entries to the minor parks (BB, DQ, PI, TL, WWS). These may or may not be used on the same days as you go to the major parks. However, if you went to TL in the morning, DQ in the afternoon, and club hopping at PI in the evening of one day you would have used three of the six entries. (Note that leaving and returning to the same minor park on the same day does not use an extra entry.)
If you go to minor parks only on one day and do not go to a major park you do not use up one of your major park days.
If you were to go to a Water Park in the morning and then one of the major parks for the remainder of the day you would have used one minor park entry and one day of major park entry.
Note that with the MYW ticket unless you have the hopper option you can only go to one major park per day. Unless you have the Water Fun option you cannot go to a minor park without upgrading or purchasing a separate ticket.
(I work at one of the water parks in Tickets/Guest Services/Greeter)