IFRS 15 Revenue from contracts with customers

I read the standard, but I am wondering if the standard only relate Revenue from contract with customers? which standard applies to Cash Sales as an item of Revenue? because the issue of contracts does not apply in over the counter cash sales, am I correct to say that IFRS 15 appliers only to Credit Sales? please clarify me on this because on cash sales, the 5 steps to be applied in order to determine if revenue is recognizable is out! there is no need for a contract there! the performance obligation is done immediately at the point of sale! the transaction price is ever-ready so no need to determine! no need to allocate the price and yes the performance obligation is being satisfied immediately at the point of sale!

For Cash Sales, does IAS 18 still applies?