Account Receivable basically refer the amount that customers owe to entity once they purchase goods or rendering services on credit. In most case, these receivables are expected to be collected in less than one year.
One the entity believe that these account receivables could be collected in less than one year, then the account classification of account receivables should be under current assets.
However, in some case those receivables could not collect in less than one year. We can know these based on the business practices, contract or agreement.
In the case that receivable could no collect in less than one year, the account classification could be class into non-current assets at book value.
Sales, Sales Revenues or Revenues are what appear in the top of income statement, and they are mean the same thing.
Sales Revenues are the amount of sales the company generated during the period of time. And this is normally show the net amount.
For example, your company sales 1,000,000 units computers during the year and its selling price of computer per unit is 1,000 USD.
The Revenues that appear 1,000,000,000 USD in the income statement of your entity.
These amount are the money that will inflow to the entity.
However, the official word to use in the income statement what prepared by using IFRS is Revenue.