Touch payment is the process of using Mifare and NFC to make secure payments using a variety of different devices such as credit cards, debit cards, smart cards and smartphones. The application allows the user to pay using their device at a point of sale terminal using a quick and secure process.
Contactless payment is an easy and secure way to pay for purchases costing £30 (limits vary depending on the country) and under. You can tell if your card is contactless as it will have a contactless image on the front or back of your card.
On devices that support contactless payment there is an ability to spend over £30 by verifying yourself on the device. E.g. through a passcode or fingerprint which can confirm your identity.
Apple Pay is an application of touch payment which is a mobile payment or digital wallet service provided by Apple Inc which works using Apple Pay compatible devices. Apple Pay does not require specific contactless payment terminals but works with existing NFC POS terminals.
Google Wallet is mobile payment or digital wallet services created by Google which allows its users to store data such as credit cards, debit cards, loyalty cards and gift cards on their mobile phone. Google wallet does not require special contactless payment terminals but works with existing NFC POS terminals.