Escrow as it relates to real estate is a process of holding money and documents in a secure account while two parties complete a purchase.
Escrows are usually held by a Title and Escrow company.
This gives the buyer and seller peace of mind that the transaction is safe and that the buyer will not be able to take the money and run.
The escrow account ensures that the buyer has the necessary funds and that the seller will receive them when the transaction is complete.
See also close of escrow.