accounts recievable are collectible payments from the customers. if you rendered service for say 100.00 and you allowed the customer to pay you within a month, that means your customer owe you 100.00. you have every right to collect it and technically speaking that money belongs to you even if it is not in your possession yet. that is the concept of accounts receivable - it is your money and money is an ASSET.

accounts payable is the exact opposite, this time assume that you are the customer. if someone rendered you a service and allowed YOU to pay him within a month for the same fee (100.00) then YOU OWE him 100.00. he has the right to collect it from you. it is your obligation to pay him the amount due hence, it is called PAYABLE - your obligation/liability

hope its clear enough. goodluck