Unlike the cartoon the tick box is not a container for a dog’s ticks but rather an element or user interface control used in computer programs. Tick boxes are also known as check boxes. A check boxes usually only have two states, checked (ticked) or not checked (not ticked). There are check boxes with a third state, tristate check boxes. This third state indicates that the check box hasn’t been to set to either state (undecided).
Check boxes are generally used to indicate true or false, yes or no or to confirm something. It is commonly used on the internet when a visitor registers on a web site. They are presented with a check box they must tick to confirm that they have read and understood the terms and conditions of the site.