Accidental damage means damage caused in an accident to your home, if you have Home Insurance, or contents, if you have Contents Insurance.
You will be covered for accidental damage if you choose the Comprehensive Cover option for your policy.
Some things are excluded, like scratching, chipping or denting caused by normal use.
Check out the PDS for more information.
Under the Basic Cover option, you will still be covered for accidental glass breakage.