The Slide Master is a part of the presentation template. It controls the overall formatting and object placement for the presentation. Note Master, Handout Master and Title Master are responsible for the corresponding Note, Handout and Title templates.
To view these Masters, on the View menu click Master. You will see that those masters contain the same amount of text.

As a rule, there is no need to count Slide Master, Note Master, Handout Master and Title Master. So you can switch these settings of the AnyCount word count tool off if you do not need to translate them.