could please explain to me what is the cash represent? It is the unused cash in petty cash? Or what else it is?

To illustrate, assume that on March 15 Laird's petty cash custodian requests a check for $87. The fund contains $13 cash and petty cash receipts for postage $44, freight-out $38, and miscellaneous expenses $5. The general journal entry to record the check is: Mar. 15 Postage Expense Freight-out Miscellaneous Expense Cash (To replenish petty cash fund)