what does '[price]+VAT' mean?

It will cost you £144

It means they haven't added VAT and are telling you it's extra. The cost to you is £144. UK law is that in shops VAT has to be included in the price, so in everyday life you don't notice it, but anywhere else they have the choice to do it either way as long as it's clear.

It's all related to how VAT works. If you were a VAT-registered business, the cost to you would be £120. You'd still have to pay £144, and then put the £24 VAT on your next VAT return and get it back that way. So if this is a business that sells a lot to other businesses, it's more helpful to their customers to give the price that way. But as an ordinary private person, the "ultimate consumer", you take the full hit of VAT and have to pay £144.

It means what it says really, £120 + VAT means it will cost you £120 +the vat,which at the moment adds 20% to the price,so total price would be £144, if a price says including vat then its just that,It could say £120 including vat,so all you would pay is £120 because the tax is included in the price.

It will mean price excluding VAT, VAT is added on to a product after the initial purchase price so it will be £120 + 20%, most websites include VAT in the quoted price when you make a purchase, its mainly wholesalers which quote the price excluding VAT and postage and add it on after