VAT stands for value added tax, and is the United Kingdom sales tax. The current rate is 20%.
Although VAT is charged on the majority of items, this does not include most music or printed materials.
If you live within the United Kingdom then VAT will be charged.
If you live outside the United Kingdom (e.g. in America) then you do not pay VAT, so the EX-VAT/EX-TAX prices apply.